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/ 



A PRACTICAL TREATISE 

ON PURE FERTILIZERS 



A 

PRACTICAL TREATISE 

ON 

PURE FERTILIZERS; 



AND THE 



CHEMICAL CONVERSION 

■'• OF 

ROCK GUANOS, MARLSTONES, COPROLITES, AND 

THE CRUDE PHOSPHATES OF LIME AND 

ALUMINA GENERALLY, 



INTO VARIOUS 



VALUABLE PRODUCTS. 

' ' '^r CGPYRIGI-. i 

CAMPBELL MORFIT, M.D., pSc^Siro}: 

M 

FORMERLY PROFESSOR OF APPLIED CHEMISTRY IN THE 

UNIVERSITY OF MARYLAND. 



With Twenty-Eight Illustrative Plates, or Construction Plans, 
drmun to Scale Measurements, 



NEW YORK: 

D. VAN NOSTRAND, PUBLISHER, 

23, MURRAY STREET, AND 27, WARREN STREET. 

1872. 



ENTERED ACCORDING TO THE ACT OF CONGRESS IN THE YEAR 1872, BY 

CAMPBELL MORFIT, 

IN THE clerk's OFFICE OF THE DISTRICT COURT OF THE UNITED STATES FOR THE 
STATE OF MARYLAND, 






PREFACE. 



This treatise is founded upon the special 
studies and large professional experience 
of the author in the technology of the 
mineral phosphates of lime and alumina. 
All of its teachings are submitted, there- 
fore, as practical knowledge, setting forth 
the subject systematically, in its most 
improved relations to science and econo- 
mics. 

The illustrations, which, with few ex- 
ceptions, are new, have been drawn large 
to a scale and as actual construction-plans, 
so that they may be fully expressive with- 
out long descriptions. Their creditable style 



vi PREFACE. 

is due to the draughting skill of Mr. 
H. Herbert Lewis, a talented mechanical 
engineer, who worked out the author's 
original designs. 

London, 

November iith, 1872. 



— -siT-^s^^^kr^-e — 



TABLE OF CONTENTS. 

CHAPTER I. 

PAGE 

The General Relations of the Subject - - i-6 



CHAPTER n. 

The Raw Materl\ls. — Comparative Solubility of the 
Crude Phosphates. 

Bone-black ; Bone-ash ; Apatite ; Phosphorite ; Spanish 
Phosphorite ; Welsh Phosphorite ; German Phosphorite ; 
Russian Phosphorite ; Austrian Phosphorite ; Copro- 
lites ; Wicken Coprolites ; Calais Coprolites ; Rossa or 
Guaymas Guano ; Sombrero Guano ; St. Martin's Phos- 
phate ; Marlstones ; South Carolina Phosphate ; French 
Phosphate; Cooperite or Navasa Guano ; Orchila Guano. 
— Analytical table of the comparative composition of 
the crude or natural phosphates of Lime. — Sulphuric 
acid ; Brown oil of vitriol ; Chamber acids ; Table of 
strengths. — Hydrochloric acid ; Table of strength.— Crude 
ammonia liquor from coal-gas and bone-black works. — 
Table of the supply and value of nitrogenous wastes. — 
Woollen refuse ; Leather clippings ; Dried blood ; Dried 
flesh ; Carne cozida ; Greaves or cracklings ; Human 
excrements ; Sewage ; Suggestions for the conversion of 
the latter into ammonia salts ; Morris and Penny's pro- 
cess ; J. Berger Spence's and Dunn's process. — Sulphate 



viii CONTENTS. 



of ammonia ; Chloride of ammonium. — Sulphate of po- 
tassa ; Chloride of potassium. — Carbonate of potassa ; 
Salt of tartar ; Pearl ash. — Lime ; Carbonate of lime ; 
Chalk ; Whiting ; Hydrated sulphate of lime. — Nitrate 
of soda .... - 7-66 



CHAPTER III. 

Chemical Data in Connection with the Raw Materials 
OF Artificial Fertilizers. 

Tri- or bone-phosphate of lime ; Di- or neutral-phosphate of 
lime ; Bi- or superphosphate of lime ; Precipitated phos- 
phate of lime ; Colombian phosphate of lime ; Sulphite 
of calcium phosphate. — Phosphate of magnesia. — Car- 
bonate of lime ; Organate of lime ; Sulphate of lime. — 
Fluoride of calcium ; Chloride of calcium. — Oxide of 
iron ; Phosphate of iron. — Oxide of aluminium ; Phos- 
phate of alumina. — Organic matters. — Silica and sand. 
— Water . - . . _ 67-91 



CHAPTER IV. 

The Grinding and Sifting Apparatus. 

Burr-stone mills ; Roller-mill ; Chasers ; Revolving sifter ; 

Blake's crusher ; Howel-Hannay's centrifugal mill - 92-107 

CHAPTER V. 

The Plant. 

Steam-boiler and engine ; Roasting furnace ; Platform and 
its accessories ; Elevator ; Lift ; Acid reservoir ; Mixer ; 
Stone digestion vats ; Solution vats ; Syphon ; Monte- 
jus; Precipitation vat ; Drying kiln ; Wash vat ; Evapo- 



CONTENTS. ix 



rating pan ; Mixing machines ; Can's disintegrator ; 

Poole and Hunt's mixer - - - - 108-146 



CHAPTER VI. 

The Arrangement of the Factory Plant - - 147-152 

CHAPTER Vn. 

The Rationale of the Processes for Refining the Crude 
Phosphates of Lime. 

Diagram of the progressive operations and their effects - 153-161 

CHAPTER Vni. 

The Manufacture of Precipitated Phosphate of Lime. 

First fractional treatment or purge for the removal of car- 
bonate of lime ; Second fractional digestion for the solu- 
tion of the tri-phosphate of lime constituent ; the vacuo- 
precipitation vats ; the ammonia-generator ; Air-pump ; 
Filtration in vacuo ; Reclamation of the ammonia-preci- 
pitant for repeated use indefinitely ; Utilization of the 
purge liquor - . - _ . 162-202 

CHAPTER IX. 

The Manufacture of Colombian Phosphate of Lime. 

First process : The use of whiting as precipitant ; Horizontal 
sieve ; Composition of the product ; the utilization of the 
mother-liquor or wash. Second pi'ocess : The use of 
iron and aluminium impurities of the mineral, as precipi- 
tant ----_. 203-225 



X 



CONTENTS. 



CHAPTER X. 

The Manufacture of Di-Phosphate of Lime. 

Morfit's process (A) : Porcelain-lined vat ; Morfit's process 
(B) ; J. Thomas Way's process ; Ernest Deligny's pro- 
cess ; Way's chloro-phosphate of lime and the method 
of making it . - - - -226-276 

CHAPTER XI. 

The Method of Reclaiming the Chloride of Calcium 
Mother-Liquor in Profitable Forms. 

As pure chloride of calcium ; as chloride of ammonium and 
hydrated sulphate of lime by means of sulphate of ammo- 
nia or gas-liquor ; by means of sulphate of potassa as 
chloride of potassium ; by means of phosphate of 
soda ------ 277-287 

CHAPTER Xn. 

The Principles of the Super-Phosphating Processes. 

The maximum yield by pure tri-phosphate of lime ; the falla- 
cies of the usual methods ; the maximum yield by bone- 
ash ; by coprolites and marlstones ; Analyses - 288-297 

CHAPTER XHI. 

The Manufacture of Pure " Super-Phosphate". 

Composition of the products from pure tri- and di-phosphates 

oflimg - - • - - -29S-302 



CONTENTS. 



CHAPTER XIV. 

The Manufacture of Pure and Wholly Soluble Bi- 
Phosphate of Lime. 

The turbine ; the vacuo-leaching vat - - -303-314 



CHAPTER XV. 

The Manufacture of " Commercial Super-Phosphate". 

Composition of the product from various crude bases. — The 

wells ----- -315-326 

CHAPTER XVI. 

The Manufacture of Horsford-Liebig's and other 
Phosphatic Baking-Powders. 

The process of manufacture ; the directions for use ; Brown 
or bran bread ; Bread for gouty patients ; Confectioner's 
cakes ; White bread. — The steam evaporating-pan - 327-338 

CHAPTER XVII. 
Gerland's Sulphite of Calcium-Phosphate. 
Its composition, properties, and manufacture ; Its uses as a 
fertilizer ; as a disinfectant. — The chemical analysis of 
the product - - - . -339-359 

CHAPTER XVIII. 

The Chemical Treatment of"Redonda Guano" and "Alta 
Vela Guano" and Mineral Phosphates of Alumina and 
Iron generally, for Conversion into Fertilizers. 

Rcdonda guano ; Alta Vela crust ; A. B. R, phosphate rock ; 
Analytical table of their comparative composition and 
value ; Method for converting them into potential ferti- 
lizers ; Digestion vats of stone - . _ 360-377 



CONTENTS. 



CHAPTER XIX. 

The Mineral Phosphates of Alumina and Iron as Raw 
Material for the Manufacture of Alum and other 
Useful Products. 

Peter Spence's process for making alum, sulphate of alumina, 
crude phosphoric acid and phosphates ; J. Berger 
Spence's and Peter Dunn's processes for removing am- 
monia from illuminating gas ; for the manufacture of 
phosphates of ammonia and lime.— Tovvnsend's pro- 
cess ------ 378-392 



CHAPTER XX. 

The Mineral Phosphates of Alumina and Iron as Raw 
Material for Defecating Sewage. 

Their application in purifying and utilizing town sewage ; 
Forbes's processes ; Price's processes ; Morfit's "mother- 
water" as substitute for Alta Vela and Redonda guanos ; 
comparative composition of the sewage precipitates ob- 
tained by the use of the " mother-liquor" and sulphuric 
solution of Alta Vela guano - - -393-401 



CHAPTER XXI. 

The Profitable Utilization of the Phosphat-Alumina 
Precipitate from Sewage as Raw Material for Various 
Products. 

For the reclamation of its nitrogenous matter as material for 
the manufacture of ammonia salts ; as raw material for 
the manufacture of alum and pure phosphates of alumina 
and lime ; as aluminate of soda or ready saponifier and 
common salt. — Phosphate of alumina in the manufacture 
of sugar ; in dyeing ; as a glaze for pottery - - 402-418 



CONTENTS. xiii 



CHAPTER XXII. 

Special Fertilizers and their Preparations. 

The physical and chemical structure of soils. — Normal ferti- 
lizer ; Universal Dunger ; Fertilizer for cereal crops ; 
for leguminous plants ; for gramineous crops ; for sugar ; 
for root crops - - - . -419-431 

CHAPTER XXIII. 

Formulae for the Chemical Analysis of Phosphatic 
Materials and Products. 

The chemical and ethical principles involved. — Instructions 
for the full analysis of bone-ash and mineral phosphates 
of lime ; of mineral phosphates of alumina and iron ; 
of "commercial superphosphate"; of compound ferti- 
lizers ------ 432-484 

CHAPTER XXIV. 

The Commercial Valuation of Crude and Refined 

Fertilizing Materials - - -4'?5-5io 

CHAPTER XXV. 

The Mode of Using Hydrometers and Thermo- 
meters . _ . . -511-519 

CHAPTER XXVI. 

Acid and Water-Proof Cements and Paints - 520-530 

Index - - - - - . -531-546 



ERRATA. 



Page 35.— In the heading of the table, read " SOg,"/^^ «' SO." 
74. — In the sixth line from the top, read " O^" for " O." 
95. — In the sixth line from the bottom, read "f,"/or " 3." 
loi. — At the bottom line, fead "fig. 3,^' for "fig. I." 
III. — At the eighth line from the top, read "D,"/or "o." 
116. — At the fifteenth line from the top, read "G,"/or "d." 
120. — At the seventeenth line from the top, read "a a," /or "aa." 
120. —At the twenty -second line from the top, read " a," /or " /^." 
191. — At the seventeenth line from the top, read " /;," /or "/." 
192. — At the eighteenth line from the top, read "r,"/or "jc." 
254. — At the last line, read "bone-ash, "_/(?;' "bone." 



A LIST OF THE ENGRAVED PLATES 
OR CONSTRUCTION PLANS. 



PLATE 

1. ROLLER MILL 

2. REVOLVING SIEVE 

3. BLAKE'S CRUSHER 

4. HOWEL'S CENTRIFUGAL MILL 

5. PLATFORM, LIFT, AND ELEVATOR 

6. DETAILS OF LIFT AND ELEVATOR 

7. MIXER 

8. DIGESTER OR SOLUTION VAT 

9. TROLLEY FOR BRINGING UP CARBOYS 

10. MONTE-JUS 

11. PRECIPITATION VAT ... 

12. DRYING KILN 

13. EVAPORATING PAN 
14. 



15- 



CARR'S MIXING MACHINE 



16. GROUND PLAN OF A FACTORY ARRANGEMENT 

^7- I BATTERY OF PRECIPITATION VATS, \VITH AMMONIA- 

18. j GENERATOR 

19. VACUUM FILTER, WITH 4IR-PUMP AND MONTE-JUS 



PAGE 

5 

20 

35 

50 

65 
80 
98 
no 
123 
140 
155 
175 
195 
215 

225 
245 
265 
28s 
305 



XVI 



A LIST OF PLATES. 



PLATE 

20. HORIZONTAL SIFTING AND STRAINING MACHINE 

21. PUG-MIXER... 

22. SOLUTION VAT COMBINED WITH VACUUM FILTER 

23. DRAINERS ... 

24. SUPER-PHOSPHATE WELLS OR PITS 

25. FILTERING STANDS 

26. I APPARATUS FOR THE TREATMENT OF MINERAL PHOS 

27. j PHATES OF ALUMINA 

28. DOUBLE-PAN FOR MAKING ACID-PROOF CEMENT AND 



PAGE 

350 
370 
395 
420 
440 
460 
480 



PAINT ... 



500 



PURE FERTILIZERS. 



CHAPTER I. 

THE GENERAL RELATIONS OF THE SUBJECT. 

The fructification of soils has its natural 
pabulum, undoubtedly, in the sewage of 
cities, towns, and habitations ; and it is de- 
sirable, both as respects agricultural inte- 
rests and the public hygiene, that thoroughly 
efficient means should be devised for uti- 
lizing this resource judiciously. Until this 
is done, the food required by growing crops 
must be supplied through the media of arti- 
ficial fertilizers. The manufacture of these 
products has become, consequently, an enter- 
prise of great magnitude, which is daily 
extending its area ; so that abundant sup- 
plies of the basis-material are indispens- 
able. Fortunately, the beneficence of Nature 



PURE FERTILIZERS. 



vouchsafes to us vast deposits of this basis- 
material, which she has distributed through- 
out the surface of the globe in the form of 
mineral phosphates, and as a temporary sub- 
stitute for sewage, while our enterprise and 
skill may remain at fault in managing the 
latter with a perfect facility.* These mineral 
phosphates consist of the various kinds of 
" Rock Guano," Coprolites, the fossils of 
Marlbeds, and the minerals Apatite and 
Phosphorite. 

The chief and valuable constituent of them 
is bone-phosphate of lime. In some few in- 
stances, phosphate of alumina is the prevail- 
ing constituent. 

All of these varieties of the mineral phos- 
phates differ from the typical phosphate of 
lime, which is bone-ash, in having a very 
dense, compact physical structure, owing to 
the peculiar state of aggregation of their che- 
mical elements. These elements vary with 
the kind of mineral phosphate, but besides 
tri-phosphate of lime, are commonly water, 

* Their geological distribution is explained fully in an 
interesting paper by VV. J. T. Dyer and A. H, Church, at 

pp. 159-185, vol. ii of Practice with Science. 



THE GENERAL RELATIONS. 



organic matter, silica, sulphate lime, carbon- 
ate lime, together with aluminium and iron 
oxides and phosphates. Some of them have 
only a secondary value as agricultural powers, 
while the others are objectionable, because 
they dilute the mass unprofitably. In an- 
other, and far more serious sense, however, 
their presence impairs the usefulness of the 
raw mineral ; for the latter, even when 
powdered finely, is by their cementing action 
rendered rather passive to decomposing in- 
fluences, and consequently a slow fertilizer. 

I say slow, because I do not share the 
opinion of many sagacious chemists, that 
phosphates of alumina and iron are without 
fertilizing effect ; nor yet that it is indispen- 
sable to change the chemical structure of the 
mineral phosphate of lime in order to give it 
action as a manure. They have inertia in 
those respects undoubtedly ; but it is my be- 
lief that the need of phosphoric acid by the 
growing crops is so great as to give them the 
energy to draw it from the most difficult 
source if none easier should be accessible. 
At the same time the strain which is thus 
put upon the assimilating powers of the 

B 2 



PURE FERTILIZERS. 



plant must weaken its constitution and im- 
pair the quantity as well as the quality of the 
harvest. 

Upon the ground of expediency, therefore, 
and to economize time, labour, and money, 
this fault of the mineral phosphates should 
be corrected by a proper chemical treatment, 
preliminary to their application to soils. That 
is, they must not only be finely powdered, 
but converted into forms which are promptly 
sensitive to the solvent action of aqueous so- 
lutions of carbonic and organic acids, very 
dilute acetic acid, ammoniacal and potassic 
salts, and of the corresponding influences of 
the soil and plants as exerted during the 
progress of vegetation. 

The usual method of destroying the iner- 
tia, or passive condition of mineral phos- 
phates, is to act upon them with sulphuric 
acid which should convert their tri-phosphate 
of lime into soluble bi-phosphate. This plan 
is perfectly sound in principle ; but, on ac- 
count of the slovenly mode of carrying it out 
generally practised, variable quantities of the 
raw phosphate remain undecomposed, and, as 
a consequence, proportional amounts of free 
sulphuric acid are introduced. 



MORFlToii the Mann fact fur o/'Ferff 




Sijeciallv desif^iiHi for 1)'. McitiH s Woi'k on FerultZfiis 



rX^ C!':'.60,PaierTiDSi.erRow 



THE GENERAL RELATIONS. 



Here, then, consequently, are a profligate 
waste of two materials, a want of uniformity 
in the product, and a wide extent of dilution, 
by reason of the sulphate of lime which is 
formed, to say nothing of the disadvantage 
of the free sulphuric acid. 

What is wanted, then, are methods, simple 
and economical, for changing not merely the 
physical constitution of the mineral phos- 
phates, but also their chemical temperament, 
and in such a manner as to convert them into 
fertilizers at once concentrated and potential. 
These latter qualities are important, more es- 
pecially on the score of package and freight 
or transportation charges in extensive coun- 
tries, like the United States of America, 
where distribution of the products is mostly 
in small lots, to the interior of scattered and 
often remote districts. In such cases, the 
necessary or desirable dilution may be done 
by the farmer himself, and with suitable as 
well as inexpensive materials which abound 
at his door, and thus save him needless out- 
. lay. 

The chemical mind has been very active in 
suggesting ways of accomplishing the needed 



ROLLER IVIILL. 



Plate 1. 



-7^ 



IJHU 




FRONT ELEVATION 



SCI\lf. OF FEET 
J f ±- 



cliilW iVa^iJiiiNl loir IV. MurtV 3 Wijrk cti l''finili;-.'>j i 



Vii k-'eia Bro^iic;. D?.yiitSan. 1 -iii ^ 



Ttim ■ :ck C9.60.PaifiiTiDSterRow 



PURE FERTILIZERS. 



improvement. Treatment in furnaces with 
fluxes, and boiling in pans with salts of dif- 
ferent kinds, in order to render the phospho- 
ric acid constituent soluble, are the methods 
most commonly met with in books. The 
use of acids of several kinds, and in varied 
manner, also constitutes the substance of 
many recorded processes. 

But, in most cases, the chemical agent em- 
ployed is either itself an undesirable element 
to import into the fertilizer, or the mode of 
use is expensive, by reason of the agent not 
producing incidentally some tangible result 
to repay fully its cost. Then, too, there is 
the bulkiness of the raw phosphate, which 
renders the usual methods both troublesome 
and defective in economy. 

No plan of instruction is equal to the che- 
mical agricultural and commercial require- 
ments of the case which does not remedy 
these deficiencies. This consideration, there- 
fore, is held paramount in the processes of 
the following chapters. Self-compensating 
throughout, they will deliver the products in 
the most valuable forms with the least pos- 
sible manufacturing expense and waste. 



CHAPTER 11. 



THE RAW MATERIALS. 



The raw materials involved in the manufac- 
ture of artificial fertilizers are the animal and 
mineral phosphates of lime, sulphuric acid, 
hydrochloric acid, crude ammonia liquor, 
sulphate of ammonia, chloride of ammonium, 
sulphate of potassa, chloride of potassium, 
carbonate of potassa, lime, and nitrate of 
soda. 

The sources of the chief class, that is the 
phosphates, are all natural, the several indi- 
viduals being bone-black, bone-ash, apatite, 
phosphorite, coprolites, marl-stones, and the 
" rock guanos". 

Bone-Black. 

This material, known also by the title of 
"Animal Charcoal", is made by calcining 



PURE FERTILIZERS. 



bones in a manner to drive off all the volatile 
matters except carbon, which is left with the 
phosphate of lime. This residue thus formed, 
when ground to powder, is sold to sugar re- 
finers for decolorizing their solutions. After 
having been used and ''revived'' several times, 
its bleaching power has become exhausted, 
and then it is sold either as a manure or for 
conversion into ''superphosphate''. It con- 
tains a large amount of organic matter, more 
particularly when blood has been associated 
with it in the decolorizing or refining opera- 
tion. 

Bone- Ash. 

This is a greyish-white powder obtained by 
calcining raw-bones, in open vessels, so as to 
get rid of the moisture, organic matter, and 
carbon ; as these associates would interfere 
with the economy and convenience of trans- 
portation from distant countries where cattle 
abound and are killed for their hides, tallow, 
and bones. The supplies come mostly from 
the La Plata Districts of South America, and 
the Baltic, Mediterranean, and Black Sea 
ports, where the process of manufacture is 
conducted so wastcfully that the valuable 



THE RAW materials. 



ammonia distillate does not receive any con- 
sideration. 

The tri- or bone-phosphate of lime in this 
ash, as well as in the bone-black, is pecu- 
liarly sensitive to the assimilating action of 
growing crops. For example, one part of its 
phosphate is soluble in 6800 parts of car- 
bonic water, according to Warrington's ex- 
periments; and this solubility is even greater 
when alkaline salts are present. 

Both the bone-black and bone-ash are such 
superior fertilizers for direct application to 
the soil, that it would be profligate to use 
them as raw material for conversion into 
" superphosphate". So great and growing is 
the demand for these two materials, that their 
market price has advanced twenty per cent, 
within the last few years. 

Apatite. 

This is a hard mineral, sometimes crystal- 
lized and at others foliated or conchoidal, 
which is found generally in thin seams in 
crystalline or volcanic rocks. It varies in 
colour from light green to iron-stone red. 
The principal localities are Norway, Sweden, 



lo PURE FERTILIZERS. 

Switzerland, Bohemia, Saxony, Bavaria, 
Canada, New York, and New Jersey. In 
order to obtain a fair average sample, it is 
necessary to grind an entire ton, owing to the 
difficulty of excluding foreign minerals in 
mining it. 

According to Voelcker, the Norway apatite 
is always free from fluoride of calcium, which 
is present, usually, in the other varieties. 

The Canadian apatite is crystallized, crys- 
talline, granular, and massive, and of a sea- 
green, olive green, greyish, or reddish colour. 
It abounds, according to T. S. Hunt, in the 
Laurentian limestones of North Elmsley and 
North Burgess, where it forms numerous 
beds eight to twenty-four inches thick and 
about ten feet broad. 

The closely cemented structure of this 
mineral, even when finely powdered, makes 
it unsuited, in an economical sense, for direct 
application to soils. It must be previously 
converted into precipitated phosphate or su- 
perphosphate, for which purposes it is most 
eligible on account of its high content of lime 
phosphate and low proportion of waste con- 
stituents. 



THE RAW MATERIALS. ii 

The commercial supply of apatite is limited, 
owing to the difficult accessibility of its 
sources. 

Phosphorite. 

The best qualities of this material are found 
at Estramadura in Spain, and Amberg in 
Bavaria. In both of these localities it 
abounds, but does not reach foreign markets 
in any quantity, because of the great expense 
of mining labour, and of the difficulties of 
inland transportation at the sources. It 
derives its name from its property of be- 
coming phosphorescent when heated. 

It is found in thick beds flanked with apa- 
tite and quartz. It is fibrous in structure, of 
a light yellow colour, and very hard, as well 
as difficult to powder. It is a very superior 
raw material for conversion into refined phos- 
phates ; and to this preparatory treatment it 
should be subjected in order to render it a 
prompt and economical fertilizer. 

Welsh Phosphorite. 

The phosphatic beds at Cwmgwnnen in the 
Lower Silurian series of North Wales has an 



12 PURE FERTILIZERS. 

area, according to W. J. T. Dyer and A. H. 
Church, of four miles long by a width of 
eighty yards and a thickness of fifteen inches. 
It is worked by adit levels driven in from the 
hill side, which it intersects almost vertically. 

German Phosphorite. 

Recent geological surveys have revealed 
very extensive deposits of this mineral in the 
districts of Staffel, Limburg, Hinterland, 
Wetzlar, Oberlahn, Unterlahn, the borders of 
the river Lahn and Dill, and other portions 
of the right basin of the Rhine. 

" It lies, generally, in diabase and shale 
overlapped or underlaid by lower and middle 
Devonian and by diluvial beds. The whole 
region is full of seams, beds and veins of 
black, red, and brown hematites." 

On account of its immense mass, the mine- 
ral of the Staffel and Limburg beds can only 
be mined by blasting. It is an amorphous 
solid, of a brownish-yellow or fawn-grey 
colour, with a splintery fracture ; but there 
are two varieties, one of which is friable and 
the other is soft. 

Though it contains some calcium fluoride 



THE RAW MATERIALS. 13 

and carbonate, alumina, and oxide of iron, it 
is, nevertheless, a good raw material for re- 
fining purposes, and should be subjected to 
this preparatory treatment instead of being 
applied, in its natural powdered state, to the 
soil. 

The analysis, by Fresenius, in the table at 
page 30, represents a selected sample, doubt- 
less ; for that which forms a deposit of about 
four thousand German acres, near the Lahn 
river in Nassau, is several per cent, less rich. 
Its composition, according to Voelcker, is as 
follows : — 



Moisture - 


- 




- 0-36 


Water of combinat 


ion 




- 1-85 


Phosphoric acid (= 


= 3CaO, P05 65' 


19) 


- 29-86 


Lime 


- 




- 42-31 


Magnesia - 


- 




0-30 


Sulphuric acid 


- 




0-65 


Carbonic acid 


- 




- 2-86 


Oxide of iron 


- 




- 4-43 


Alumina and loss in analysis - 




- 6-33 


Insoluble siliceous 


matter 




- iro5 




1 0000 



Russian and Anstrian Phosphorite. 

The great phosphorite zone in Russia 
occupies an area of 20,000 square versts : 



14 PURE FERTILIZERS. 

extending from the Volga, near Simbirsk, 
into the Desna district of Smolensk ; and 
thence, after a real or apparent break, into 
the government of Grodno. Grewingk's ana- 
lysis gives the following composition for the 
mineral : — 

Organic matter and constitutional water - 4*702 



Moisture or accidental water - 


- 0910 


Silica _ . - 


- 42-965 


Fluorid of calcium - 


- 3-535 


Proto-carbonate of iron 


- 3-847 


Carbonate of magnesia 


- I -602 


Oxide of iron 


- 0*922 


Alumina - - - 


- 5-027 


Phosphate of alumina 


- 1-874 


Tri-phosphate of lime 


- 32-950 


Potassa . - - 


- 0751 


Soda - . . 


- 0-593 


Sulphuric acid 


- 0-076 



99754 

Further southward, on the Zanks, on the 
Dniester, in Russian Podolia, and in the 
Bukowina, there are also deposits of phos- 
phorite, which Schwachofer describes as very 
rich on the average. The composition of the 
nodular portions resembles that of apatite. 



THE RAW MATERIALS. 15 

Coprolites. 

True coprolites are not fossil excrements, 
as has been supposed, but worn and rounded 
fragments of fossil bones of a peculiar organ- 
ization. They are found in the green sand 
and crag of the lower chalk formation and 
adjoining strata. 

The false coprolites, as those of Suffolk, 
are a mixture of fossilized excrements, fish- 
bones, rolled stones, etc., forming beds in the 
more recent tertiary strata between the coral- 
line crag and the London clay. 

The coast of Suffolk and Cambridgeshire, 
England, are extensive localities for these 
phosphatic materials. They are also found 
abundantly in France and Germany, and to 
a small extent in Canada. 

Owing to the fluoride of calcium which 
they contain, hydrofluoric acid is evolved 
during the process of superphosphating them, 
and waste as well as discomfort ensue conse- 
quently. The presence of a large amount of 
carbonate of lime involves, also, a waste of 
acid ; to say nothing of the considerable pro- 
portion of alumina and oxide of iron, which 
not only are profligate constituents as regards 



i6 PURE FERTILIZERS. 



the consumption of the acid, but the means 
of rendering the "superphosphate" perma- 
nently damp. These circumstances, and the 
fact that their valueless constituents will di- 
lute the product to an extreme degree, reduce 
the coprolites to an inferior rank as a raw 
material, for the manufacture of refined phos- 
phate products. Nevertheless, they are em- 
ployed extensively for the purpose in Great 
Britain, — perhaps on account of their regular 
abundance and low price. They do not make 
" superphosphate" of good quality by the 
usual processes ; nor are they so profitable 
for the methods of this treatise as even the 
" South Carolina Phosphate"; and those in- 
ferior kinds of coprolites known as the 
"Wicken Coprolites" from Cambridgeshire 
and Bedfordshire; and "Calais Coprolites" 
from the Pas de Calais in France. Either of 
the two latter is to be obtained abundantly at 
a low price, and the following analyses will 
show their composition. The samples were 
obtained from a trustworthy source, and re- 
present fairly the average character of the 
respective deposits. They may be considered 
as typical members of the class of low grades 
of mineral phosphates of lime. 



THE RAW MATERIALS. 



17 



WICKEN COPROLITES. 


COPROLITES FROM PAS DE 
CALAIS. 


(Morfit.) 




(Morfit and B. W. Gerland. ) 


Moisture - - _ 


1-66 


Moisture 


0-610 


Loss by ignition 


2-97 


Sand, pyrites, etc., in- 




Silica, sand, & pyrites 24-46 


soluble in HCl. - 


33-340 


Fluoride of calcium - 


2 -02 


Silicic acid 


1-490 


Sulphate of lime 


1-53 


Fluoride calcium 


2-100 


Carbonate of lime 


10- 1 6 


Sulphate of lime 


2-487 


Lime (as silicate and 




Carbonate of lime - 


11-360 


organate) 


6-40 


Lime as silicate, etc. 


7-360 


Tri-phosphate of lime 


35-66 


Tri-phosphate lime 


29-150 


Oxide of iron - 7-56 




Tri-phosphate mag- 




Alumina - - 4-07 


14-30 


nesia - - - 


2-552 


Phosphoric acid 2-67 




Oxides of iron, 2111 








Alumina, 2-730 


^10-541 




99-16 


Phospho. acid, 5-700 

] 






00-990 



Rossa or Giiaymas Gitano. 

This is a very superior rock guano from 
Rossa Island, 28-3 north latitude, and 110-46 
west longitude, near Guaymas, in the Gulf of 
California. It contains a portion of its phos- 
phate of lime in a di- or neutral state, and is 
almost wholly free from constituents which 
would waste acid. It is in hard lumps, but 



PURE FERTILIZERS. 



can be reduced to fine powder without diffi- 
culty ; and in this latter form is well suited 
for mixing with highly ammoniacal manures. 

For the purposes of this treatise, it may be 
considered almost a pure material, as the 
foreign matters are all excluded, by the action 
of the hydrochloric acid, in the very first stage 
of the refining processes. 

The analysis in the table represents a 
sample which I examined several years ago ; 
but, though the deposit is large, none has yet 
been brought into this market. 

Sombrero Guano. 

This is a rock guano constituting the entire 
structure of one of the Windward Islands in 
the Carribean Sea, called Sombrero. It is 
most probably a bone breccia ; as pieces of 
bone are found occasionally in the mass. It 
is not very hard, and forms a light yellow 
brown powder. 

I was the first to recognise the agricultural 
value of this mineral phosphate, and give it 
professional support when it was the object of 
great prejudice. The following analyses by 
Voelcker, of cargoes imported in 1871, show 



THE RAW MATERIALS. 



19 



that notwithstanding a greater dampness, 
owing to being mined now below the level of 
the sea, it reaches the market in quality as 
good as that of the earlier importations which 
are represented by my figures in the analytical 
table at pages 30, 31. 



Water and '\ 
Organic > 
matters j 

Phosphoric \ 
acid j 

Lime - - - 

Magnesia, "^ 
Ox. iron, f 
Carbonic C 
acid, etc. j 

Sand & Silica 



2-99 


5-08 


9-42 


9-19 


5-49 


9-52 


689 


21-20 


32-32 


30-84 


30-98 


30-84 


32-86 


30-48 


31-16 


27-82 


45-96 


47-65 


44-98 


44-33 


45-83 


44 77 


45-18 


35-72 


II-2I 


15-48 


13-53 


14-59 


14-57 


14-14 


15-45 


14-56 


7-52 


•95 


I-I9 


1-05 


1-25 


I 09 


1.32 


•70 


lOO'OO 


loo-oo 


1 00 00 


lOO'OC 


100-00 


100 00 


100-00 


100-00 



There is one portion of the island which 
gives a mineral of the following composition, 
according to analysis by Evans and Jones ; 
but none of it has yet been mined for market. 



Moisture and water of combination 

Silica 

Carbonate of lime 

Phosphate of lime 

Phosphate of alumina 

Alkaline salts - 



6-01 


lo-io 


4'43 


43 '3 5 


30-20 


5-91 



1 0000 



C 2 



20 PURE FERTILIZERS. 



St. Martins PhospJiate. 

This mineral is from the island of St. 
Martin's, but has not been sent forward in any 
large quantity. The following analysis by 
Voelcker shows the composition of what may 
be considered an inferior sample. 



Water and loss on heating 


- 8-66 


Carbonic acid 


- 11-57 


Phosphoric acid - 


- 2476 


Lime - - - 


- 4541 


Alumina, ox. iron, and magnesia 


- 6-37 


Insoluble silicates 


- 3-23 




lOO'OO 



South Carolina Phosphate. 

This material comes from the neighbour- 
hood of the Ashley river, South Carolina, 
United States of America. It is in the form 
of hard nodules called Marlstones. The fish 
beds from which it is obtained are forty to 
fifty miles in extent. It may be ground with- 
out difficulty, and forms a powder sometimes 
of an olive-grey shade, at others of a brown- 
ish-buff colour, and soluble in acids. 

Of all the mineral phosphates of lime which 






z 
o 

I 



UJ 

O 



lO o 



> 

CO 

O 

z 



o 

> 

UJ 





bJ 
J 
< 

U 



THE RAW MATERIALS, 21 



are available, in abimdant and regular supply , 
these marlstones are among those best suited 
for the purpose of this treatise. Their ratio 
of carbonate and organate of lime is not un- 
profitably large where hydrochloric acid is 
cheap ; and the solution of the iron and 
alumina constituents may be kept down in 
considerable degree by skilful manipulation. 
The remaining associates of the phosphate 
of lime constituent are merely valueless and 
not diluents or promoters of waste of acid. 
Their proportion of phosphate of lime, 
though only a moderate average, is thus 
really present in profitable degree. Another 
advantage is that the material may be bought 
at a comparatively lower price than minerals 
of the same class. 

The composition of that kind of *' South 
Carolina Phosphate" which gives a fawn- 
coloured powder, and as imported in 1870-1, 
is shown by the analytical table at pages 

30, 31- 

Another variety, whose powder is olive- 
greyish in colour, and now coming forward 
(1872) in greater or lesser quantity, has the 
following chemical constitution, according to 



22 



PVRE FERTILIZERS. 



the full analysis of a sample from a recent 
cargo : — 



"SOUTH CAROLINA PHOSPHATE." 




(Morfit and B. W. Gerland. ) 






Moisture . - _ 




. 


I'll 


Organic matter 




- 


1-34 


Insoluble, silica, sand, etc. 




- 


11-56 


Pyrites - - _ 




- 


1-24 


Silica, dissolved by HCl. 




- 


'Z6 


Fluoride calcium 




- 


2-62 


Sulphate lime 




- 


4-1 r 


Carbonate lime 




- 


14*02 


Lime, as organate, silicate, aluminate 


- 


9-1 1 


Tri-phosphate lime 




- 


42-13 


Tri-phosphate magnesia 




- 


4"43 


Oxide iron 


1-83 


\ 




Alumina - - - 


2-0/ 


\ 


8-39 


Phosphoric acid 


4-49 


) 





100-92 

A third variety of this phosphate is now 
being brought forward also, from Williman's 
Island, Prince William's parish, Beaufort 
County, S.C, formed by inlets on the eastern 
coast, about fifteen miles from the Atlantic 
Ocean. It comprises nearly 1600 acres, with 
a bed of phosphate running throughout, 



THE RAW MATERIALS. 23 

which latter has been calculated to yield 
10,000,000 tons. 

Dr. A. Voelcker, who examined this phos- 
phate, has reported that a careful and detailed 
analysis of the finely ground sample (un- 
washed) taken from the bulk at the Stores 
yielded the following results : — 



Moisture - - - - 191 

^Organic matter and water of combination 4*05 

Phosphoric acid _ _ . 26'23 

Magnesia - - - - -24 

Lime _ _ - _ 3978 

Potash - - - - '20 

Soda - - _ . -65 

Chloride of sodium - - - '05 

Sulphuric acid _ _ _ 2*50 

Oxide of iron - - - i'85 

Alumina and a little fluorine - - 4'64 

Insoluble silicious matter & soluble silica 15 '31 

Carbonic acid - _ _ 2'6o 



lOOOO 



*Containing nitrogen - - - "09 

Equal to ammonia - - - "ii 

"The presence of traces of nitrogenous or- 
ganic matter in this material appears to indi- 
cate its organic origin." 



24 PURE FERTILIZERS. 

" Williman's Island Guano resembles near- 
est in character the Cambridgeshire Copro- 
lites." 

French PJwsphate. 

This is most probably a species of bone 
breccia, for, though of rocky character, fossil 
bones are found with it in some of the open- 
ings. 

It extends over a wide area of the depart- 
ments of the Lot and Garonne, the Lot and 
the Aveyron in France, where it is found in 
detached veins and small pockets underlying 
the grey limestone on the highest plateaux of 
the mountains between the rivers Lot and 
Aveyron. 

The solid veins run generally from eastward 
to westward ; and the loose boulders are 
found embedded in a ferruginous looking 
clay and sand. It gives a light fawn coloured 
powder. 

The following analyses by Voelcker of 
several of the cargoes of 1871 show that 
it is a very high quality of mineral phos- 
phate. 



THE RAW MATERIALS. 













"Ar- 


" Philo- 


" Hana- 


Components. 


"Topaz." 


"Denia." 


"Maria." 


"Rifle." 


mandMa- 


mene." 


ton." 













rianne." 






Water and loss ') 














by heating j 


3-45 


315 


4"io 


4-29 


6-03 


4'94 


2-23 


Phosphoric acid 


3607 


36-64 


33-05 


34-89 


33-80 


34-90 


37-60 


Lime 


48 '43 


4865 


48-46 


4709 


48-25 


4962 


4652 


Alumina and \ 
















oxide of iron, 
















magnesia, >• 


9-56 


9-04 


1 2 '40 


1 1 -02 


9-24 


889 


13-04 


carbonic 
















acid, etc. ) 
















Insoluble sili- \ 
cious matter j 


2-49 


2*52 


1-99 


271 


2-68 


1-65 


•61 




lOO'OO 


1 00 00 


lOOOO 


100 00 


lOO'OO 


1 00 00 


lOQ-OO 



Navasa Guano or Cooperite. 

The island which furnishes this mineral is 
on the coast of Hayti, in latitude 78 deg. 
25 min. N., and longitude 75 deg. 2 min. W. 
As sent into the market by the proprietors, it 
is in brown lumps which give a powder like 
that of hematite. The very large proportion 
of iron and aluminium compounds, which it 
contains, distinguishes it from all other 
mineral phosphates of lime ; and owing to 
this and other characteristic features I gave 
it, some years ago, the name of Cooperite, 
after the enterprising Captain of the Com- 
mercial Marine who first brought it into 
notice. 



26 PURE FERTILIZERS. 

My analysis in the table at pages 30, 31 
represents its composition at that time ; and 
it is uncertain whether the quality has since 
improved. 

Those cargoes which arrive now are very 
variable in their degree of moisture ; and 
there is also a want of uniformity in the 
quantitative relation of the phosphoric acid 
constituent. 

The annexed analyses represent the com- 
position of a superior and an inferior sample ; 
so that the mean of the two may be accepted 
as the present average quality of the mineral. 

In my recent refining experiments on a 
large scale, I obtained from it about fifty-five 
per cent, of precipitated phosphate of lime in- 
dependent of the iron and alumina with which 
it was associated. The difficulty of prevent- 
ing the solution of a large portion of the 
oxide iron and alumina along with the phos- 
phate lime is the only objection to this raw 
material for superphosphating purposes, as it 
is cheap and in abundant supply. At the 
same time, the precipitated product which I 
obtained from it by my processes was of 
good quality and gave a "superphosphate" 



THE RAW MATERIALS. 27 

much superior in every respect to that which 
any raw phosphate material, except bone-ash, 
could be made to yield. 



NAVASA GUANO OR COOPERITE. 






(MorfitatidB. IV. Gerland. 


) 








Moisture - - - 




I 
3 '94 




2 
3*13 


Organic matter and loss by ignition 


- 


5-07 


- 


5-32 


Sand, silica, etc. 


- 


4-43 


- 


4-37 


Fluoride calcium 


- 


1-27 


- 


1-40 


Sulphate lime 


- 


I -09 


- 


I -2 1 


Lime, as organate, silicate, aluminate 


- 


4-80 


- 


III2 


Carbonate lime 


- 


4-63 


- 


6-52 


Tri-phosphate lime 


) 


55-62 


{ 


45-52 


Tri-phosphate magnesia 


J 


1-83 


Oxide iron 


1 








Alumina - - - 


[ 


19-86 


- 


22-24 


Phosphoric acid 


J 









I007I 99-86 

Orchila Gttano. 

This material is best known in the United 
States market. It is brought from Orchila, 
an island in the Carribean Sea, lat. 1 1 deg. 
50 min. N., and long. 66 deg. 14 min. W., 
and belonging to Venezuela. Its natural 
form is that of a rather damp, fawn-coloured 



PURE FERTILIZERS. 



powder. Its loose texture is advantageous for 
its direct application to the soil ; but the pro- 



NOTE. — Charles P.Williams {CJicmical Neivs, xxiv, 306; 
and Journal of the Chemical Society, x, 269, i %'J2) has re- 
ported some very interesting results of a course of experi- 
ments upon the comparative solubility of several crude 
phosphates of lime. Care was observed to separate the 
dissolved phosphate of lime from any foreign associates in 
the liquor, so that its amount might be determined exactly. 
Molybdate of ammonia was the re-agent employed. Ac- 
cording to that Chemist : — 

One part of finely ground bone, containing 5678 per cent, 
of tri-phosphate of lime, dissolved in 5-698 parts of 
water saturated Avith carbonic acid gas. 

One part of finely ground South Carolina Phosphate, con- 
taining 57*89 per cent, of tri-phosphate of lime, dis- 
solved in 6-983 parts of water saturated with carbonic 
acid gas. 

One part of finely ground Orchila Guano, containing 49*67 
per cent, of tri-phosphate of lime, dissolved in 8-009 
parts of water saturated with carbonic acid gas. 

One part of finely ground Bone-Ash, containing per 

cent, of tri-phosphate of lime, dissolved in 8-029 parts 
of water saturated with carbonic acid gas. 

One part of levigated Apatite from Canada, containing 
89-27 per cent, of tri-phosphate of lime, dissolved in 
140-840 parts of water saturated with carbonic acid 
gas. 

One part of ground Apatite from Canada, containing 89-27 
per cent, of tri-phosphate of lime, dissolved in 222-222 
parts of water saturated with carbonic acid gas. 



THE RAW MATERIALS. 29 

portion of phosphate of lime which it contains 
renders its money value comparatively small. 
As this latter is associated with a very large 
amount of carbonate lime and other profligate 
components, the guano is not well suited for 
refining purposes. The analytical figures in 
the annexed table represent a sample which I 
obtained direct from the proprietor's agent. 

The foregoing examples may be considered 
the commercial representatives of their class 
of materials ; for, with few exceptions, they 
are all now in the market. It is only the 
comparative expense of mining and trans- 
portation that makes any exceptional in- 
stances, and even those will disappear as 
soon as the contingencies of supply and de- 
mand may justify the bringing forward of 
present reserves. 

It is to be hoped, however, that in the 
meantime new and even cheaper sources, in 
rich abundance, may be found and developed ; 
for, as phosphate of lime is the basis of crops, 
and bountiful harvests cheapen bread, which 
forms the staff of life, such incidents would 
grow as well a humanitarian influence in the 
grandest and most practical sense. 



30 



PURE FERTILIZERS. 



Analytical Table of the Comparative 
Crude Phosphates 



Components. 


Rossa Gu- 
ano from 
the Gulf of 
California. 

(Morfit.) 


Apatite 

from 
Canada. 

(T.S.Hunt.) 


Apatite 

from 
Norway. 

(Voelcker.) 


Phospho- 
rite from 
Spain. 

(Ogston.) 


Phospho- 
rite from 
Germany. 
(Frese- 
nius.) 


Bone or tri-phosphate ) 
lime and magnesia J 


S3-08 


91-20 


90-74 


8o-6S 


74-64 


Neutral or diphosphate ) 
lime - - -\ 


18-03 


— 


— 


— 


— 


Carbonate lime - 


— 


— 


— 


4-26 


3 '43 


Lime, with organic \ 
acids, silica, and > 
alumina - - ) 


— 


— 


4*59 


1-83 


1-34 


Fluoride calcium 


— 


7 60 


— 


•II 


526 


Chloride calcium 


— 


78 


1-61 


— 


— 


Phosphate alumina - 


— 


— 


1 1-66 


— 


— 


Phosphate iron - 


— 


— 




— 


Oxide aluminium 


0-25 


— 


traces 


1 -50 


108 


Oxide iron 


015 


— 


— 


6-42 


Sulphate lime - 


810 




— 


— 


— 


Potassa salts 


1 - 




_ 


_ 


o-sS 


Soda salts - - - 


— 


— 


_ 


0-52 


Organic matters 


980 


— 


— 


— 


— 


Water, constitutional - 
Water, accidental 


362 


— 


0-43 


•20 


2-45 


Carbon - - _ 


— 


— 


— 


— 


— 


Sand and silica - 


6*20 


0-90 


1-64 


12-34 


4-83 




99-53 


100-48 


10067 


99-92 


ICO- 5 5 



THE RAW MATERIALS. 



31 



Composition of the Natural, 
of Lime. 



Bone-Ash 
from 
South 

America. 

(iMorfit.) 


Bone-Black 
from Sugar 
Refineries. 

(Morfit.) 


Sombrero 
Guano. 

(Morfit.) 


True 
Coprolites, 
Cambridge. 

(Way.) 


False 

Coprolites, 

Suffolk. 

(Herepalh). 


Marlstones 
or South 
Carolina 

Phosphate. 

(Morfit.) 


Cooperite 

or Navasa 

Guano. 

(Morfit.) 


Orchila 
Guano. 

(Morfit.) 


7031 


58-10 


67-06 


57-09 


55-49 


52-21 


4680 


45-84 


1082 


8-8o 


5-34 


13-27 


13-40 


[14-32 


1-92 


19-61 


79 


— 


6-97 


3-41 


— 




10-37 


274 


— 


— 


— 


4-33 


1-43 
1-66 

5-12 


— 


— 


— 


— 


— 


362 


5-57 


\ 


6-78 


\ 


1 -60 


— 


1-95 
3-13 


1-78 
2-14 


r6i 
•80 


889 


320 
11-62 


11-36 


1 


— 


i-io 


traces 


traces 


J 


370 




— 


— 


-86 


•80 


•70 


— 


I-02 


— 


•20 


} -So 


1 -49 


-61 


•65 





traces 


— 








5-36 






8-00 


602 


6-93 






• 8-6o 


— 


■ 4-05 


I 6-26 


— 


— 





) 8-42 






3-52 




' 


3-05 


4-74 


12-54 


-' 


19-50 


— 


— 





— 


— 


— 


9-20 


4-00 


-68 


6-93 


12-45 


13-96 


4-50 


1-24 


ioo'34 


99-80 


100-08 


99-98 


99-57 


100-43 


10067 


10026 



32 PURE FERTILIZERS. 

SiilpJmric Acid. SO3. HO = 49. 

The composition of this acid in its pure 
state is as follows : — 

Dry sulphuric acid (SO3) - 40'00, or per cent. 81-63 
Water of constitution (HO) 9*00 „ 18-37 



Chemical equivalent - 49-00 „ 100-00 

The range and strength of affinities which 
pertain to this acid render it the most im- 
portant and useful chemical agent in the arts. 
There are very few salts of other acids which 
it will not decompose. Moreover, it is cheap 
and abundant. 

Sulphuric acid is met with in commerce of 
two strengths, the first being known as Oil of 
Vitriol having a specific gravity of i "846, and 
the second, called Brown Oil of Vitriol, with 
a specific gravity of 1700. This latter is the 
acid as it comes from the leaden chambers in 
which it is made. By subsequent concentra- 
tion in platinum or glass vessels it becomes 
Oil of Vitriol or Monohydrated Sulphuric 
Acid (SO3 HO). 

The brown or chamber acid has the formula 
SO, HO + HO approximately. There are yet 



THE RAW MATERIALS. 33 

weaker acids known in the factories but not 
met with in commerce and having respectively 
the specific gravity i'45o, i'35o, i'25o. 

Oil of vitriol is a transparent, colourless 
liquid of oily consistence which freezes at 
29 deg. below o deg. F., and boils at 620 deg. 
F. It distils then without being decomposed, 
the fumes given off being those of dry sul- 
phuric acid (SO3). 

Sulphuric acid has a great affinity for water, 
and when one is added to the other so much 
heat is evolved that great care must be ob- 
served in mixing them. 

The dry acid (SO3) is not known in com- 
merce, and both the oil of vitriol and brown 
acid are solutions of dry acid in water, of dif- 
ferent strengths. The latter is much more 
economical than the former for manufacturing 
purposes, as all the expense of concentration 
is saved, strong acid not being required. 
There are thirteen carboys to the ton. 

In the manufacture of fertilizers, the con- 
sumption of sulphuric acid is so great that 
the cost of the carboys which contain it and 
the expense of transporting them are import- 
ant elements of consideration. It is advis- 



34 PURE FERTILIZERS. 



able, therefore, to manufacture the acid on the 
spot or else to locate the manure works in the 
immediate neighbourhood of a sulphuric acid 
factory. 

As differences of strength are due to degree 
of concentration, the weaker the acid the less 
expensive will be its use. 

One pound of oil of vitriol of specific 
gravity i'846 \s practically equivalent to : — 

1-26 lbs. of brown sulphuric acid of sp. gravity, 1700 
176 „ chamber „ „ i*450 

2-20 „ „ „ M 1-350 

2-91 „ „ „ „ i'25o 

Every per cent, or pound of tri- or bone- 
phosphate of lime requires practically for its 
decomposition into soluble bi-phosphate 
of lime : — 

0'64 lbs. of concentrated oil of vitriol of sp. gr., \'Z\6 
082 „ brown „ „ 1700 

1-14 „ chamber sulphuric acid „ i'450 

142 „ M „ „ r350 

1-87 „ „ „ „ 1-250 

For the decomposition of each per cent, or 
pound of carbonate and organate of lime, 
there would be wasted 




Sprcully desigiie.i fca' D!^ Morfits Work an ir'ei-uiizer 



THE RAW MATERIALS. 



35 



0-98 lbs. 


of concentrated oil of vitriol of 


sp. gr. 


, 1-846 


1-26 „ 


brown ,, 


,, 


1700 


176 „ 


chamber sulphuric acid 


>i 


1-450 


2-20 „ 


>» » 


>» 


1-350 


2-91 „ 


V >> 


„ 


I 250 



Urcs Table of the Quantity of Concentrated (SO HO) 

and Dry Snlphnric Acid (SO) in 100 parts 

of Dilute Acid at different densities. 





Liquid 


Dry 




Liquid 


Dry 




Liquid 


Dry 


Specific 


Acid 


Acid 


Specific 


Acid 


Acid 


Specific 


Acid 


Acid 


Gravity. 


in 


in 


Gravity. 


in 


in 


Gravity. 


in 


in 




100. 


100. 




100. 


100. 




100. 
32 


100. 
26-09 


1 "8460 


100 


81-54 


1-5503 


66 


53-82 


1-2334 


I -8438 


99 


80-72 


I 5390 


65 


53 'oo 


I -2260 


31 


25-28 


1-8415 


98 


79-90 


1-5280 


64 


52-18 


I -2184 


30 


24-46 


1-8391 


97 


7909 


I-5170 


63 


51-37 


I •2108 


29 


2365 


I -8366 


96 


78-28 


I -5066 


62 


50-55 


I -2032 


28 


22-83 


I -8340 


95 


77-46 


I -4960 


61 


49 74 


1-1956 


27 


22-01 


1-8288 


94 


76-45 


I -4860 


60 


4892 


1-1876 


26 


21-20 


1-8235 


93 


7583 


I -4760 


59 


48-11 


I-I792 


25 


20-38 


i-8i8i 


92 


7502 


I -4660 


58 


47-29 


1-1706 


24 


19-57 


I -8026 


91 


7420 


I -4560 


57 


46:48 


I-I626 


23 


18-75 


I -8070 


90 


73-39 


I -4460 


56 


45-66 


I -1549 


22 


17-94 


1-7986 


89 


72-57 


I -4360 


55 


44-85 


I -1480 


21 


17-12 


I -7901 


88 


7175 


I -4265 


54 


44-03 


I-I4I0 


20 


16-31 


1-7815 


87 


70-94 


1-4170 


53 


43-22 


I -1330 


19 


15-49 


17728 


86 


70 12 


1-4073 


52 


42-40 


I -1246 


18 


14-68 


17640 


85 


69-31 


1-3977 


51 


41-58 


I-II65 


17 


13-86 


I 7540 


84 


68-49 


1-3884 


50 


4077 


I -1090 


16 


13-05 


1-7525 


83 


6768 


1-3788 


49 


39-96 


r-1019 


15 


12-23 


1-7315 


82 


66-86 


I -3697 


48 


3914 


1-0951 


14 


11-41 


I -7200 


81 


66-05 


I -3612 


47 


38-32 


I -0887 


13 


10 -60 


I -7080 


80 


65-23 


1-3530 


46 


37-51 


I 0809 


12 


9-78 


1-6972 


79 


64-42 


1-3440 


45 


3669 


1 -0743 


II 


8-97 


I -6860 


78 


63 60 


I -3345 


44 


35-88 


I 0682 


ID 


81s 


I -6744 


77 


62 78 


1-3255 


43 


35-06 


I -0614 


9 


7-34 


I -6624 


76 


61-97 


1-3165 


42 


34-25 


1-0544 


8 


6-52 


1-6500 


75 


61-15 


I -3080 


41 


33-43 


I -0477 


7 


571 


I -6415 


74 


6034 


I 2999 


40 


32-61 


1-0405 


6 


489 


I 6321 


73 


59-52 


I -2913 


39 


31-80 


I -0336 


5 


4-08 


I -6204 


72 


58-71 


1-2826 


38 


30-98 


1-0268 


4 


3 26 


I -6090 


71 


5789 


I -2740 


37 


30-17 


I -0206 


3 


2-44 


15975 


70 


5708 


1-2654 


36 


2935 


1-0140 


2 


1-63 


I -5868 


69 


56-26 


1-2572 


35 


28-54 


10074 


I 


o-8i 


1-5760 


68 


55-45 


I -2490 


34 


27-72 








I -5648 


67 


5463 


I -2409 


33 


26-91 









D 2 



MORFIT oil ih.\ hauil<'(tiuv.<'rFeHiU:j'r.s- ^ 




Plate 5. 



Blake's Crusher _ Front Elevation & Plan 



FIG. 3 




FIG. 2 



(o) 



koi 



t, 



'M 



oooooooooo O n n nT^ .° o O O O O o o o 
O O O o O O O O n r, \^^ OOOOOOOOO O O 



;^° ° ° o 




dti- 



Uj^i 



jr 




LXr 



I H 



iy-.-jJlv >.teaj<iii-,l la V. Moifiia Work * ta-uliif ■ 



lijhnf: s 'Z-.6'- rt.'f3T£<5" 



36 PURE FERTILIZERS. 



Hydrochloric Acid. HCl =36-5. 
In a pure gaseous state, it has the following 
composition : — 

Chlorine (CI) - - 35-5, or per cent. - 97-26 
Hydrogen (H) - - lo „ - 274 

Chemical equivalent - 365 „ - loooo 

Hydrochloric acid is rarely found free 
except in certain mineral waters and volcanic 
exhalations. It is diffused, however, in 
nature to a wide extent, as chloride of 
sodium and other chlorides or hydrochlo- 
rates. 

Commercial hydrochloric acid is a solution 
of dry acid in water, and as made, direct, from 
chloride of sodium, it has the specific gravity 
1-170 to i"247. That which is found in com- 
merce, however, rarely has a greater strength 
than specific gravity riyo. This latter is, in 
Great Britain and France, a by-product of 
the soda manufacture obtained by condensing 
the vapours, from the decomposing furnaces, 
in Gossage's coke towers ; and may be 
bought there to any extent at 12 to 15 
shillings per ton. 



THE RAW MATERIALS. 37 

A factory for fertilizers should form a part 
of every soda-works, in order that the large 
incidental product of hydrochloric acid may 
be utilized advantageously on the spot. 

Chemically considered, one equivalent of 
dry or gaseous hydrochloric acid (HC1=36'5) 
is equivalent to one equivalent of dry sul- 
phuric acid (SO^ = 40). Therefore, as the 
commercial hydrochloric acid of specific 
gravity riyo contains 34*25 per cent, of 
gaseous acid (HCl), one pound of it is equiva- 
lent to 0*46 pounds of concentrated oil of 
vitriol of specific gravity i "846 or o'58 pounds 
of brown oil of vitriol of specific gravity 1 700. 

For the same reason, every vo carbonate 
of lime would require for its decomposition 
2" 1 3 of hydrochloric acid (I'lyo) and form 
I'll of dry chloride calcium (CaCl). 

So also, every vo of tri-phosphate lime 
needs for its solution r37 of this hydro- 
chloric acid ; and there is produced 071 of 
dry chloride calcium (CaCl). 

As hydrochloric acid, whether weak or 
strong, always gives off fumes, at even or- 
dinary temperatures, it is necessary to be 
careful in manipulating with it. The reser- 



38 



PURE FERTILIZERS. 



voir which is to hold it and the pipes which 
are to convey it must be closed, consequently, 
and lined with stearic pitch, gutta-percha, or 
caoutchouc. 



life's Table sJiotving the per cent, of Gaseous or Dry Acids 
in Hydrochloric Acid of different densities at 62° F. 



Specific 
Gravity. 


Gaseous 
Acid 
(HCl). 


I -2000 


40-777 


1-1982 


40-369 


1-1964 


39-961 


1-1946 


39-554 


I-I928 


39-146 


1-1910 


38738 


1-1893 


38-330 


1-1875 


37-923 


1-1857 


37-516 


I-1846 


37-108 


1-1822 


36-700 


I-1802 


36-292 


I-1782 


35-884 


1-1762 


35-476 


1-1741 


35-068 


I-I72I 


34-660 


I-17OI 


34-252 


i-i68i 


33-845 


1-1661 


33-457 


1-1641 


33-029 


1-1620 


32-621 


I-I599 


32-213 


1-1578 


31-805 


I-I557 


31-398 


I-I537 


30-990 



Specific 
Gravity. 



•1575 
-1494 

-1473 
-1452 

-1431 
•I4IO 
•1389 
■1369 

•1349 
•1328 
•1308 
•1287 
•1267 
■1247 

1226 
'1 206 
•I185 

1 1 64 

"43 
1123 
1 102 
1082 
106 1 
1041 
1020 



Gaseous 
Acid 
(HCl). 



30-582 

30-174 
29-767 
29-359 
28-951 
28-544 
28-136 
27-728 
27-321 
26-913 
26-505 
26-098 
25-690 
25-282 
24-874 
24-466 
24-058 
23-650 
23-242 
22-834 
22-426 
22-019 

2i-6u 
21-203 
20-796 



Specific 
Gravity. 



-0960 
-0939 
-0919 
-0899 
•0879 
-0859 
-0838 
-0813 
-0798 
-0778 
-0758 
-0738 
-0718 
-0697 
•0677 
-0657 
-0637 
•0617 
•0597 
•0577 
■0557 
■0537 
■0517 



Gaseous 

Acid 

(HCl). 


Specific 
Gravity. 


Gaseous 
Acid 
(HCl) 


20-388 


1-0497 


10-194 


19-980 


1-0477 


9-786 


19-572 


1-0457 


9-379 


19-165 


I -0437 


8-971 


18-757 


1-0417 


8-563 


18-349 


1-0397 


8-155 


17-941 


1-0377 


7-747 


17-534 


1-0357 


7-340 


17-126 


10337 


6-932 


16-718 


1-0318 


6524 


16-310 


1-0298 


6116 


15-902 


1-0279 


5-709 


15-494 


1-0259 


5-301 


15-087 


1-0239 


4-895 


14-679 


1-0220 


4.486 


14-271 


1-0210 


4-078 


13-683 


i-oi8o 


3-670 


13-456 


i-oi6o 


3262 


13-049 


10140 


2-854 


12-641 


1-0120 


2-447 


12-233 


10100 


2-039 


11-825 


I -0080 


I -63 1 


11-418 


1 -0060 


1-124 


11010 


I 0040 


0816 


10-602 


I 0020 


0-408 



THE RAW MATERIALS. 39 

Crude Ammonia Liquor. 

The most common form of this material is 
''gas liquor \ one of the products incident to 
the destructive distillation of bituminous coal 
in the manufacture of illuminating gas. It 
is formed also, and largely, as a secondary 
product, in the manufacture of animal char- 
coal from bones, and in the destructive 
distillation of bituminous schists, refuse oil- 
cake, woollen waste, leather clippings, and 
nitrogenous, organic matters generally. 

Theoretically, every 14 per cent, of nitro- 
gen in the raw material should give 17 per 
cent, of ammonia ; but, owing to various 
difficulties and complexities in the mechani- 
cal, as well as chemical, circumstances of the 
practical conversion, the actual results do not 
approach this estimate. 

When the raw material contains sulphur, 
as in the case of coal, then the liquor distilled 
from it will hold the ammonia, principally as 
carbonate, but associated with sulphide, sul- 
phate, chloride, and ferrocyanide. As ob- 
tained from other sources, it is almost wholly 
a solution of carbonate of ammonia. 



40 PURE FERTILIZERS. 

The coal-gas liquor, which is in fact a 
solution of crude ammonium salts, comes 
over with tar, and is condensed in the 
hydraulic main ; but the tar forms a separate 
stratum, and the two may be separated 
readily by decantation or drawing off from 
the containing cistern or well. The volume 
of tar is greater, generally, by 20 per cent, 
than that of the ammonia liquor. 

In the manufacture of gas from coal, as 
much as 60 per cent, of the ammonia, it is 
said, remains with the gas ; but, according to 
Wright, one ton of good Newcastle coal will 
yield, nevertheless, ten gallons of liquor 
weighing 100 pounds. Pockston names 11 
to 13 imperial gallons as the usual product 
from a ton of good coal. 

Clegg states that the amount of ammo- 
niacal product varies with the temperature at 
which the destructive distillation of the coal 
is effected. Very high heat diminishes the 
product by converting a portion of the am- 
monia into cyanogen. Nevertheless, the 
usual amount of liquor obtained from one 
ton of Newcastle coal is ten imperial gallons, 
equivalent to 3-3J ounces of dry caustic am- 



THE RAW MATERIALS. 41 

monia, or a total of 30 to 32^ ounces. In 
addition, the gas retains so much more as to 
raise the actual yield of dry ammonia gas 
from one ton of Newcastle coal to six pounds 
avoirdupois. The liquor from boghead and^ 
cannel coals yields less ammonia, generally, 
than that from the bituminous coals. 

Berger Spence and Peter Dunn (chapter 
xix) propose to abstract all the ammonia re- 
tained in the gas by passing it through the 
crude phosphoric acid liquor obtained in the 
chemical treatment of mineral phosphates of 
alumina (chapter xix). The gas would be 
thus purified by the formation, simultane- 
ously, of phosphate ammonia — a very valu- 
able product. 

To make caustic ammonia from gas-liquor, 
it is only necessary to add lime (with some 
chloride of iron) to the latter in the propor- 
tion of five per cent, of its weight, and then 
to distil. The gaseous distillate passing over 
is to be received in water, which at 50° F. 
condenses 670 to 780 times its volume of am- 
moniacal gas. 

The strength of crude ammoniacal liquor 
varies with its source. It is sold usually by 



42 PURE FERTILIZERS. 

the ton at one shilling for every degree it 
may show by Twaddel's hydrometer, and each 
degree of this instrument represents 0*47 dry 
ammonia gas. 

Owing to the liquor being a mixture of 
several different ammonium salts, this mode 
of estimating the strength is very rough. A 
better, but yet only approximately correct 
method, would be to take a weighed measure 
of the liquor, neutralize it with pure hydro- 
chloric acid, evaporate it to dryness, and 
weigh the residue. In this manner I ob- 
tained two and three quarter ounces of solid 
chloride of ammonium from 16 fluid ounces 
of the liquor of a private gas-works. Assays 
of liquor from other works showed, in like 
manner, an average of nine per cent, of chlo- 
ride, or, say three per cent, of dry caustic 
ammonia. 

According to Knapp, one imperial gallon, 
or, say ten pounds, of gas-liquor yield, by 
distillation to hydrochloric acid, 31 to 39 
ounces of solid chloride of ammonium, equi- 
valent to an average of 17 '50 per cent. 

Barreswill, an eminent French chemist, 
states that 2000 litres of gas-liquor give 100 



THE RAW MATERIALS. 43 

kilogrammes of sulphate of ammonia, or in 
the proportion of 5 per cent, of the weight, 
which is equal to i^ per cent, of dry caustic 
ammonia. 

English manufacturers of fertilizers report 
to me that 1000 gallons of gas-liquor, weigh- 
ing, say, lO'ooo pounds, produce an average 
of ten hundredweight of sulphate of ammo- 
nia ; that is, about 10 per cent., equivalent to 
2*50 per cent, of dry caustic ammonia. 

The average strength of English gas- 
liquor, therefore, to be deduced from these 
data, is, in round numbers, 3 per cent, of dry 
caustic ammonia, or sixty pounds and up- 
wards per ton. 

Some idea of the extent to which this 
liquor is produced may be obtained by con- 
sidering the fact that the amount of coal con- 
sumed for gas in London alone, is nearly one 
and a half millions of tons yearly. And, as 
every city, town, hamlet, railway station, 
factory, and large farm establishment, will, 
sooner or later, have its gas-works, this 
source of ammonia-supply will become even 
richer than at present. 

In addition, however, to gas-liquor, there 



44 PURE FERTILIZERS. 



are other abundant sources of ammonia, and 
notably the manufacture of bone-black from 
bones, in which it also distils over as a crude 
liquor. 

According to Kamrodt, the nitrogen is as 
follows, in the various waste products of 
commerce : — 

Horn - - - 15 to 17 per cent. 

Feathers - - i/ ij 

Bristles - - - 9 to 10 „ 

Hide cuttings - - 4*5 to 5 „ 

Old shoes - - 6 to 7 „ 

Good woollen rags - 13 to 16 ,, 

Inferior woollen rags - 10 to 12 „ 

Ox, cow, and calves' hair - 15 to 17 „ 

Dried ox blood - - 15 to 17 „ 

Sheep's wool - - 16 to 17 „ 

Shoddy - - - 7 to 9 „ 

Wool. 

The destructive distillation of wool is an- 
other source of ammonia. Wool, when fresh, 
contains, according to Scherer, 13 to 16 per 
cent, of water. On exposure to air, 6 to 7 
per cent, of this water passes away by evapo- 
ration ; and the wool, thus dried, yields by 
calcination, 3*23 of ash. The ultimate com- 
position of wool is — 



THE RAW MATERIALS. 



45 



Carbon 


- 50-65 


Hydrogen 


7-03 


Nitrogen - 


- 1771 


Oxygen, sulphur, etc. 


24-61 




loo-oo 



The following table of the present supply 
and market values of the several kinds of 
woollen waste in England, is made from data 
furnished to me by Mr. W. G. Etchelss, 
Huddersfield : — 



Kind of Woollen Waste. 


Present 

Market Price 

in England 

per ton. 


Probable amount 

of Supply annually 

in 

Great Britain. 








£ s. d. 




I. 


Willy dust 


- 


10 


10,000 tons 


2. 


» " " 


- 


10 


— 


3- 


»> " " 


- 


10 


— 


4. 


Cutters' flocks - 


- 


700 


1,000 tons 


5- 


Shoddy - - i8s. 


to 


I 


10,000 „ 


6. 


New woollen rags or cut 
tings . - - 


■} 


10 and \ 
upwards 1 


Any quantity 


7- 


Old woollen rags or cut 
tings ... 


-} 


4 and "1 
upwards j 


Any quantity 



Leather Clippings. 

The almost unlimited supply of this waste 
material, which abounds everywhere, and 



46 PURE FERTILIZERS. 

may be collected at a nominal cost, renders it 
a very suitable basis for an ammonia process 
by destructive distillation. The quantity of 
nitrogen which it contains is always large, 
but varies more or less with the kind of 
leather waste. 

Dried Blood. 

In the extensive slaughter-houses of the 
United States of America, as well as in the 
abattoirs of France, the blood of the animals 
which are killed for food is either dried or 
solidified by coagulation, and thus econo- 
mised for market. Its condensed form and 
richness in nitrogen render it a most valu- 
able nitrogenous material for fertilizing pur- 
poses or the production of ammoniacal salts. 

Dried Flesh. 

In countries where cattle, sheep, and hogs 
abound and are killed for their hides and 
tallow and the flesh is boiled for extract of 
meat, there is a fibrinous residue which, 
when dried, becomes a most advantageous 
nitrogenous material for all the purposes of 
this treatise. The supply of it is very large. 



THE RAW MATERIALS. 47 

Human Excrements. 

This source alone, if properly utilized, 
would supply the larger part of all the am- 
monia salts that are required by mankind. 
The dejecta of each person amount per day 
to 4j lbs. ; and these dejecta, comprising 
3 lbs. of urine and 20 oz. of solid faeces, 
contain the average of 150 grains of nitro- 
gen, which is equivalent, in that element, to 
6000 grains or nearly a pound of wheat flour. 
Two hundred pounds of wheat flour are con- 
sidered a liberal annual apportionment to 
each person. 

All this wealth of fertilizing matter might 
be economised by such a municipal regulation 
as would compel the inhabitants of towns or 
cities to construct their privies with box-recep- 
tacles and a automatic, hopper arrangement, by 
which the dejecta would become mixed with 
dry earth as they fell. The deodorizing and 
absorbent properties of the dry earth would 
render the mixture easy to be handled and 
removed for further drying in heated air- 
currents. Thus prepared and powdered, it 
would then be ready for combustion with 



48 PURE FERTILIZERS. 



soda lime, according to the methods sug- 
gested at p. 53. 

In this manner, all the contained nitrogen 
would be eliminated as ammonia distillate, to 
be condensed into ammoniacal salt by means 
of sulphuric, hydrochloric, or crude phos- 
phoric acid. 

The solid residuum or calx would consist 
of sand, soda, and carbonate of lime, together 
with phosphate of lime or phosphate of soda. 
If the latter is present, it will have been 
formed from the phosphate of lime element 
of the faeces, by interaction with the soda 
under the fluxing influence of the high heat 
employed for the combustion. Indeed, the 
chemical and mechanical conditions of the 
combustion might be arranged so as to insure 
the total conversion of the phosphate of lime 
into phosphate of soda. The solid residue 
would then yield this latter as an aqueous 
solution by simple leeching with water. The 
phosphate of soda thus isolated, is a most 
valuable liquor for economising the wash or 
MOTHER LIQUOR in chapter xi. By merely 
mixing the two, an exchange of bases would 
take place, and pure phosphate of lime would 



THE RAW MATERIALS. 49 

precipitate, leaving chloride of sodium or 
common salt in solution. 

On the other hand, if the combustion 
should be managed so as to preserve intact 
the phosphate of lime element, then the soda 
may be washed out by means of water and 
evaporated to dryness for repeated use an in- 
definite number of times. 

The remainder of the solid residuum is in 
itself a valuable mineral manure, or it may 
be dried, powdered, and substituted advan- 
tageously, for earth, as the drying and de- 
odorizing material to be used in the privies. 

Sewage. 

Several of the processes now in use for the 
defecation of town sewage render the latter a 
valuable source of ammonia. The precipitate 
thus produced carries down the suspended 
organic matter of the sewage ; and this latter 
may be then isolated by merely dissolving the 
earthy portion of the precipitate in hydrochlo- 
ric or sulphuric acid. The organic matter, on 
being dried carefully, is a most potential form 
of nitrogen, for direct use as a fertilizing agent, 
as it contains the equivalent of about 7 per 



50 PURE FERTILIZERS. 

cent, of ammonia, associated with valuable 
humus matters. It forms, also, a most con- 
centrated material for combustion with soda- 
lime, to produce ammonia salts by Morris and 
Penny's process, described at p. 53 ; provided 
always that it is wholly or nearly free from 
sand and silica. 

At the same time, the decanted liquor being 
a hydrochloric or sulphuric solution of the de- 
fecating elements of the original material, is 
ready for purifying a fresh portion of sewage, 
as in the first instance ; and thus it may be 
made to serve for an indefinite number of 
repetitions of the process. The establishment, 
in this manner, of an independence of any 
possible failure in the supply of the Alta Vela, 
Redonda, or other of the mineral phosphate 
materials employed in the purification of 
sewage, is an important consideration, and 
invests the process with a capacity for emi- 
nent utility and economy. 

The ammoniacal salts are such necessary 
aids to profitable agriculture, that every 
means should be promoted to increase the 
supply of them. As a stimulus to enterprise 
in this direction, I have exposed the fore- 



IG. 2 



C 



Plate 4. 



F 



^9- 



MORFIT in /hcManii/ar/iirf o/7'c/tilizers: 



FIG. I 



FIG. 2 



FIG. 3 



I'l.Mt.- I-. 




^r- 



j 



s- 



f^ 



J) 







Si 







® 



// 



TT 




SCALE. OF FEET 



Centrifugal Mill_General View &. Details 



THE RAW MATERIALS. 51 



going details, and set forth in Chapter xi a 
simple and practicable process for reclaiming 
the ammonia of gas-liquor wherever the latter 
may be found. 

The comparative abundance and cheapness 
of the several kinds of woollen and leather 
waste deserve the most serious consideration 
in this connection. I have long given the 
subject such study as my leisure would per- 
mit, and the plan for converting these ma- 
terials into ammonia, which would be most 
likely to succeed, is one assimilating in cha- 
racter to the analytical method of estimating 
the amount of nitrogen in organic bodies by 
combustion with soda-lime. 

The principle upon which such a process 
would be founded is safe and well-established, 
and consists in the property which nitro- 
genous organic bodies have of giving off the 
whole of their nitrogen in the form of ammonia, 
when strongly heated with hydrated alkalies. 

The soda-lime employed may be reclaimed 
an indefinite number of times ; so that the 
expense on this item would be at the lowest 
possible point. But there are mechanical 
difficulties which beset the necessary arrange- 



E 2 



52 PURE FERTILIZERS. 



ment for effecting a progressive combustion 
on a large scale. My present idea is to use 
iron retorts, like those for making coal-gas, 
but longer, and with suitable valve-cocks for 
safety, and tube-attachments to convey away 
the gas and intercept the fluid portion of the 
distillate. 

The mixture of waste and soda-lime having 
been put into a series of retorts, the whole 
are to be closed and made air-tight at the 
joints by means of fire-lute. As it would 
cause a too sudden and. free flow of distillate 
to put fire under the retort throughout its 
entire length at once, the heating would have 
to be restricted at the commencement to the 
first twelve inches of the front or mouth por- 
tion of the retort, and pushed forward gradu- 
ally as the current of gas from the preceding 
part begins to slacken. 

It is necessary that a good fire should en- 
velope the top of the retort as well as the 
bottom. Indeed, it is the arrangement of the 
heating appliances, so as to produce a pro- 
gressive and perfect combustion of a large 
quantity of waste in each retort, that presents 
the chief obstacle to the installation of an 



THE RAW MATERIALS. 53 

economical and ready-working process upon 
the basis which I have suggested. As the 
obstacle is not by any means insurmountable, 
I hope that it may soon have solution by 
some competent mind and hand. 

Richard Morris and Mulgrave Daniel 
Penny, manufacturing chemists of Yorkshire, 
England, obtained a patent recently for a 
process in this direction, which they describe 
as follows: — 

" The process is for treating shoddy and 
other animal waste to obtain ammonia and 
salts of ammonia therefrom. 

'' We decompose the shoddy, or it may be 
leather cuttings, horn piths, or such-like 
animal waste, in clay or iron retorts, heated 
to a cherry red ; and we admit jets of steam 
into the retorts. Retorts like those used for 
the manufacture of coal-gas, and similarly set 
in a furnace may be employed. 

''The gases and vapours from these retorts 
are passed into a main, as in the manufacture 
of coal-gas, where tar and ammoniacal water 
are deposited. From the main, the gases and 
vapours pass into the retorts containing the 
alkaline matter. 

'' Lime is the material we commonly em- 
ploy. The lime retorts are similar, but of 



54 PURE FERTILIZERS. 

greater length, say twenty feet or thereabout. 
They are heated to a white-heat. The gases 
and vapours are passed in succession through 
the lime retorts (six retorts are a convenient 
number to employ), and then they are caused 
to enter an absorbing tower where the am- 
monia formed is absorbed by acid, by prefer- 
ence sulphuric acid. The water and the tar 
which condense in the main, and the acid in 
the absorbing vessel, contain all the ammonia. 

" The acid is drawn off from the absorbing 
vessel from time to time, and saturated by 
distilling ammonia into it from the water of 
the main. Finally, the saturated solution is 
evaporated to the point of crystallization. 

"The gas, of which the quantity is large, 
is collected in gasometers, and it may be em- 
ployed for the purposes of heating and light- 
ing. An exhauster may advantageously be 
employed to draw the gas and vapour from 
the retorts, as is usual in the manufacture of 
gas. The shoddy, or animal-matter retorts, 
are re-charged in succession, as soon as it is 
found that the material in them is spent, and 
the residue is useful as animal charcoal or as 
manure. The lime retorts are also re-charged 
from time to time, whenever the lime is found 
to have become clogged with deposit and 
spent ; the gas and vapour arc caused to pass 



THE RAW MATERIALS. 55 

first into the lime retort which has been 
longest charged, and last into that which has 
been most recently replenished. Sometimes 
we charge the last retort of the series with 
soda-lime or wdth caustic soda, in place of 
with lime, and so get a most perfect conver- 
sion of the nitrogen of the animal matter into 
ammonia. We purify the sulphate and other 
salt of ammonia by crystallization in the 
usual way, and from this ammonia salt caustic 
ammonia may be obtained by heating with 
lime, as is well understood." 

Sulphate of Ammonia. NH3, SO3, HO =66. 
This salt, when pure, is composed of — 

Ammonia (NH3) . - - i/'O, or per cent., 2575 
Sulphuric acid (SO3) - - 40*0 „ 6o'62 

Waterof constitution (HO) - 9*0 „ I3'63 



Chemical equivalent - - 66*o ,, lOO'OO 

This is the neutral sulphate obtained on a 
large scale from the water of condensation, 
produced in the distillation of coal for gener- 
ating illuminating gas, and in the calcina- 
tion of bones for making bone-black or bone- 
ash. It is manufactured, also, from stale 
urine and other animal matters. It is in 



56 PURE FERTILIZERS. 

crystals, which are colourless when pure, but 
dirty grey or brownish when crude. The 
crystals are six-sided prisms, with correspond- 
ing pyramidal tops, and • have a specific 
gravity of 175. They are very soluble in 
cold water, but insoluble in alcohol, and 
have a bitter, piquant taste. 

Sulphate of ammonia melts at 2840 F., but 
resists decomposition up to 356° F. Beyond 
the latter degree it loses ammonia, becomes 
firstly bi-sulphate, and changes finally into 
nitrogen, water, and bi-sulphate of ammonia, 
which sublimes. 

This salt is the means by which I change 
the chloride of calcium of hydrochloric solu- 
tions of mineral phosphates of lime, into 
chloride of ammonia and sulphate of lime ; 
so as to reclaim the hydrochloric acid profit- 
ably, and, at the same time, to free the preci- 
pitated phosphate of lime from any hygro- 
scopic or humid tendency. 

Each (ro) per cent, or pound of this neu- 
tral sulphate of ammonia is equivalent to 
I "32 neutral sulphate of potassa. 

For each pound (ro) of carbonate or or- 
ganate of lime that may have been dissolved 



THE RAW MATERIALS. 57 

out of the mineral phosphate by hydrochloric 
acid (2-13), there will be required 1*32 pounds 
of sulphate of ammonia, and the products 
would be — 

172 lbs. of hydrated sulph. of lime (CaO, SO3, 2HO) ; 
I'O/ lbs. of dry chloride of aminoiiium (NH3, HCl). 

Chloride of Ammonium, or Hydrochlorate 
of Ammonia. NH3, HCl=53-5. 

When pure, its composition is — 

Ammonia (NH3) - - i/'o, or per cent, 3178 
Hydrochloric acid (HCl) 36-5 „ 68 22 



Chemical equivalent - 53*5 „ 100*00 

This salt crystallizes in needles, which are 
soluble in water and alcohol. It is always 
anhydrous, and sublimes unaltered at a tem- 
perature just below redness. It is commonly 
called Sal Ammoniac. Specific gravity, i "45 
to 1*50. 

Its per cent, of ammonia is much higher 
than that of the sulphate (2575), and on this 
account, as well as for other good reasons, it 
is to be preferred for fertilizing purposes. 



58 PURE FERTILIZERS. 

Sulphate of Potassa. KO, 803=- 87 "o. 
Its composition, when pure, is as follows : 

Potassa (KO) - - - 47-00, or per cent., 54*00 
Sulphuric acid (SO^) - 40'00 ,, 46-00 



Chemical equivalent - 87-00 ,, 100-00 

This is a neutral salt in the form of colour- 
less hard crystals, which are very soluble in 
cold or hot water, and resist decomposition at 
even high temperatures. Its specific gravity 
in the anhydrous state is 2'625 ; but it varies 
from 2*623 to 2 "656 in the ordinary com- 
mercial article. • 

It is used alone or in conjunction with 
sulphate of ammonia for economising the chlo- 
ride of calcium wash liquor in the processes 
of this treatise, by precipitating the lime as 
sulphate and forming chloride of potassium. 
But it is in no sense as advantageous for that 
purpose as the sulphate of ammonia. 

Each per cent, (ro) or pound of carbonate 
and organate of lime which has been decom- 
posed and dissolved by hydrochloric acid 
(2" 1 3) from the raw mineral, requires 174 



THE RAW MATERIALS. 59 

pounds of this neutral sulphate of potassa, 
and forms — 

172 lbs. of hydrated sulph.of lime (CaO, SO3, 2HO) ; 
i'49 lbs. of dry chloride of potassium (KCl). 

This salt is a secondary or reclaimed 
product in the clarification of oils and in 
many other manufacturing" processes. Dark 
coloured crystals cost less than the bright, 
and are sufficiently pure for this process. It 
is also sent to market largely from the natural 
deposits at Stassfurt, in Prussia, and in this 
form is known commercially as kainit; which 
contains, as an average, 23 to 25 per cent, of 
sulphate of potassa, associated with 14 to 28 
per cent, of magnesia salts and 30 to 48 per 
cent, of chloride of sodium. 

Chloride of Potassium. KC1=74*5. 
Its composition is — 

Potassium (K) - 39"0, or per cent., 52*35=KO^ 63*1 
Chlorine (CI) - 35-5 „ ^yGs 



Chemical equiv. - 74*5 ,, lOO'OO 

This is an anhydrous salt which crystallizes 
in cubes or rectangular prisms, and dissolves 



6o PURE FERTILIZERS. 

in about two and a half times its weight of 
cold water. It volatilizes at a red heat with- 
out decomposing. Specific gravity i'95o. 

Carbonate of Potassa. KO, C02==69'o. 
When pure and ignited its composition is : 

Potassa (KO) - - 47'00, or per cent., 68' ii 
Carbonic acid - - 22*oo „ 3 1*89 



Chemical equivalent - 69*00 „ ioo"00 

As found in commerce, however, it is a 
more or less impure salt under the names of 
salt of tartar and pearl ash, and contains 
about 16 per cent, of water of crystallization. 

The first is in the form of a coarse granu- 
lated powder, insoluble in alcohol, but very 
soluble in water and even deliquescent. It 
fuses at a red heat without decomposing. 

Salt of tartar is refined pearl-ash, obtained 
by dissolving the latter in water, and leaving 
it to repose. The clear liquor contains all the 
caustic and carbonate of potassa, with some 
portion of the other soluble salts of the pearl- 
ash, and rests upon a sediment of insoluble 
impurities. The liquor being then drawn off 
and concentrated by evaporation, drops a fur- 



THE RAW MATERIALS. 6i 

ther portion of its foreign salts, from which it 
must be decanted. Thus largely freed from 
impurities it is finally evaporated to syrup 
and stirred into dry granular salt of tartar. 

It is employed in the processes which will 
be described for the mineral phosphates of 
alumina ; and would answer the required pur- 
poses in its crude form of pearlash. 

Lime. CaO=28. 
The composition of caustic lime when pure 



is- 



Calcium (Ca) - - 20-0, or per cent., 71 "42 

Oxygen (O) - - - S'O „ 28-58 



Chemical equivalent - 28*0 „ 100*00 

It is largely diffused in nature as carbonate 
and sulphate, and forms the basis of lime- 
stones, chalk, the various kinds of marbles, 
calcareous spars, gypsum and many other 
minerals. 

Caustic lime is obtained by calcining lime- 
stone or other carbonate of lime in suitable 
kilns. In this way the carbonic acid is driven 
off and lime remains in a ''quick" or caustic 
state mixed with more or less of magnesia, 



62 PURE FERTILIZERS. 

alumina, oxide of iron, silica, and the other 
impurities of the original raw material. 

These vary in quantity from 5 to 30 per 
cent, according to the kind of raw material ; 
and when the lime is to be employed in 
chemical equivalent proportion, the amount 
of foreign matters must be predetermined 
by analysis and excepted in the calculation. 
Any excess above five per cent, of impurities 
takes it out of the class of good lime for 
the processes of this treatise. 

Lime is in lumps, sometimes white and at 
others grey, very alkaline, and has such an 
affmity for water and carbonic acid that it 
must be kept in closed barrels protected from 
exposure to air. It is very soluble in acids, 
and forms salts with them. Hot water dis- 
solves it less readily and in less quantity than 
cold water, which latter takes it up in the 
proportion of one part of lime to every 730 
parts of water. Specific gravity 2*3 to 3*0. 

When quick-lime is sprinkled to saturation 
with water it soon begins to give off hissing 
sounds, developes great heat and thick 
vapours of volatilized water, and finally en- 
larges its volume into a fine powder or 



THE RAW MATERIALS. 63 

mass of slaked lime, which is a hydrate of 
lime=CaO, HO. 

In slaking the lime with half its weight of 
water, the temperature rises to 500*^. 

The longer it takes to fall to powder after 
the drenching with water for slakening it, the 
more impure it is. A good rich lime is never 
longer than three to five minutes in answer- 
ing favourably to this test. 

If the quantity of water is then further in- 
creased so as to give a liquid character to the 
mixture, the product is milk of lime. This 
milk must be strained through a fine sieve of 
galvanized wire cloth. 

One equivalent of anhydrous lime(CaO=28) 
corresponds with one equivalent of dry hydro- 
chloric acid (HC1=36'5) or one equivalent of 
dry sulphuric acid (503=40). 

Carbonate of Lime, 

This substance is noted in another place 
as to its more scientific relations ; so that 
it only remains to mention it here in its 
practical bearings upon the processes about 
to be described. 

The form employed is that commonly 



64 PURE FERTILIZERS. 



known as whiting. It is prepared from 
chalk, a white earthy mineral which may be 
considered, practically, as pure carbonate of 
lime. That is, its impurities are in small pro- 
portion, and mostly mechanical, and easily 
removed. It is the elimination of these 
latter which changes the chalk into whiting. 
According to Schweitzer's analysis, the chalk 
of Brighton (Sussex) cliff is composed of — 



Carbonate of lime 


- 98-57 


Carbonate of magnesia - 


- -38 


Phosphate of lime 


•II 


Oxide of iron 


•08 


Oxide of manganese 


•06 


Alumina 


•16 


Silica - - - 


- -64 




loo-oo 



The process consists in grinding the chalk, 
diffusing the powder in a large volume of 
water, and leaving to repose only so long as 
may be necessary for the subsidence of the 
heavy particles. The liquor, holding in sus- 
pension all of the finer portion, is to be drawn 
off into a vat and allowed to settle. When 
this has been accomplished, the supernatant 
water is to be drawn to waste through taps. 



THE RAW MATERIALS. 65 



and the residual white pulpy deposit dried in 
the air or in a moderately heated chamber. 

The dried mass is '' whiting'\ and so much 
more suitable than chalk as a chemical agent, 
that in many instances it will produce the 
desired effect where chalk would fail. 

Sulphate of Lime. CaO, SO3, 2 HO=86. 
Its composition is — 

Lime (CaO) ... 28-0, or per cent., 32*56 
Sulphuric acid (SO3) - - 40*0 „ 46*51 

Water of constitution (HO) - iS'O „ 20*93 



Chemical equivalent - - 86'0 ,, loo'oo 

Ordinary sulphate of lime is known as 
''ground plaster!' When this is calcined 
it becomes anhydrous, and is then called 
' 'plaster of Paris! ' 

The form relating to fertilizers is that of 
artificial hydrate, because it is much more 
active as a fertilizer than the natural ground 
gypsum. It is the solid product obtained in 
the decomposition of the wash liquor (chapter 
xi) by sulphate of ammonia or potassa, and 
then dried at 120° F. From this source it will 
retain, generally, some little of ammonia or 
potassa salt. 



MORFIT on the Mami/actiwe oFFertilU^rs. 




jx5<Ti!.Bnia& D^iSas Jj*. 



sWoritTifcmlizars. 



66 PURE FERTILIZERS. 

Nitrate of Soda. NaO, N05==85'o. 
Its composition is — 

Soda (NaO) - - - 31-0, or per cent, 36-81 
Nitric acid (NO5) - - 54-0 „ 63-19 

85-0 100-00 

This salt forms thick natural beds of great 
extent in the deserts of Atacama and other 
parts of Peru and Chili, whence it is brought 
in very large quantities. It is found also in 
the Bahia province of Brazil. As found in 
nature, it is in the form of greyish white, 
grey and yellowish, friable lumps, containing 
two to eight per cent, of impurities consisting 
chiefly of water, chloride of calcium, chloride 
of sodium, sulphate of potassa, nitrate of 
potassa, and nitrate of magnesia. 

It crystallizes in rhombohedra, the angles 
of which are not very far removed from those 
of a cube, and hence its synonyme of cttbic 
nitre. It is also known as CJiilian saltpetre. 

It is very soluble in water, but rather in- 
soluble in alcohol, and has a tendency to 
dampness, and a sharp, bitter, cooling taste. 



CHAPTER III. 

CHEMICAL DATA IN CONNECTION WITH THE 

RAW MATERIALS OF ARTIFICIAL 

FERTILIZERS. 

A PROPER understanding of the subject of 
this treatise will depend upon a knowledge 
of the internal, as well as physical, properties 
of the substances employed. 

This chapter, therefore, will be devoted to 
the study of the individual components of the 
raw materials which enter into the manufac- 
ture of artificial fertilizers. 

The most important is the phosphate of 
lime, and there are three chemical phases of 
it. The principal one is the tri-basic or bone- 
phosphate forming the structure of bones. 
This consists of three equivalents of lime in 
combination with one equivalent of phos- 
phoric acid. The second is the di- or neu- 
tral-phosphate, differing from the preceding 

F 2 



68 



PURE FERTILIZERS. 



in containing two equivalents of lime to one 
of acid, the third equivalent of lime being re- 
placed by water. The third is the bi-phos- 
phate, and consists of only one equivalent of 
lime to one of acid, with two equivalents of 
water. "Super-phosphate" is the commercial 
mixture of bi-phosphate, bone-phosphate, and 
sulphate of lime made by the action of sul- 
phuric acid on animal or mineral phosphate 
of lime. 

These distinctions of formulae will be better 
understood when expressed in tabular form 
with their relative numerical equivalents or 
values affixed. 





Symbol. 


Combining Numbers. 


Composition per cent. 




Lime. 

84-0 
56- 

28- 


Water. 

9 

18 


Phosphoric 
Acid. 


Lime. 

5385 

40-87 
2373 


Water. 

6-57 
15-26 


Phosphoric 
Acid. 


Tri- or Bone-"^ 
phosphate > 
of lime J 

Di- or Neu-"^ 
tral - phos- > 
phateoflime} 

Ei - phosphate "^ 
of lime } 


3CaO. PO5 

2CaO. PO5 f HO 
CaO. P0s + 2H0 


72-o(-i56) 

72- (-137) 
72- (=118) 


46-15 (= 100) 

52-56( = IOO) 
61-01 (- 100) 



Tri- or Bone- Phosphate of Lime. 3 CaO, 
P05=i56. 
This is the most common form, being 
widely diffused in nature as the earthy 



CHEMICAL DATA. 69 

structure of bones and the basis of mineral 
phosphates, such as apatite, phosphorite, 
coprolites, rock guanos, marlstones, and the 
like. 

It is also a component of ammoniacal 
guanos ; and the chief constituent of bone- 
black and bone-ashes. When associated with 
gelatine and other organic matters in its 
natural condition of ground bone, it breaks 
up in the soil under atmospheric influences 
into forms which are not only soluble but 
very assimilable by the growing crops. In 
the state of bone-black it is scarcely less 
soluble in the soil ; and in the form of bone- 
ash falls only a few degrees in rank of solu- 
bility below the bone-black. Weak acids 
dissolve it readily ; and those of greater 
strength not only dissolve it but convert it 
into super-phosphate by abstracting two 
equivalents of its lime. 

In like manner, the presence of acetic acid, 
carbonic acid, chloride of ammonium, certain 
potassic salts, and chloride of sodium, causes 
it to split into more soluble phosphatic salts 
or states ; and it is in this manner drawn up 
by growing crops into the vegetal circulation. 



JO PURE FERTILIZERS. 

It may be prepared artificially from an 
aqueous solution of chloride of calcium by 
the addition of an aqueous solution of basic 
phosphate of soda ; or on a large scale by 
precipitating a hydrochloric acid solution 
of bone-phosphate of lime, or even of bone- 
ash, with pure ammonia. 

Strictly considered, however, this preci- 
pitate from the latter solutions is rather a 
mixture of several phosphates of lime, all 
quite prompt to assume solubility under the 
conditions existing in soils. 

When freshly precipitated from an acid 
solution, phosphate of lime is white and in- 
soluble in water, but peculiarly sensitive to 
the solvent action of water containing only 
a small quantity of ammonia or carbonic 
acid. 

This action, though gradual, is constant, 
and extends even to the precipitated phos- 
phate in a dry state. 

As existing in rock guanos or minerals, 
tri-phosphate of lime is not only cemented 
closely by associate ingredients, but has 
naturally a physical temperament which ren- 
ders it obstinate to the action of solvents 



CHEMICAL DATA. yi 



under the ordinary conditions pertaining to 
the soil. These natural forms are conse- 
quently so very slow as fertilizers J>er se that 
chemical treatment must be practised to 
render them soluble previous to their applica- 
tion. 

This is particularly necessary when they 
are accompanied with fluoride of calcium, 
silicate of lime, alumina, phosphate of alu- 
mina, oxide and phosphate of iron. 

Di- or Neutral-Phosphate of Lime. 2 CaO, 
HO, P05=i37. 

This phosphate exists in many mineral 
waters, but is rarely found in nature to any 
extent. The only two instances in my know- 
ledge are, that of the Colombian guano from 
Maracaibo, of which the stock has been ex- 
hausted long since ; and another rock-phos- 
phate from Rossa Island near Guaymas in the 
Gulf of California. It has been formed in 
nature, as it may be in the laboratory, by the 
gradual action of water, and particularly of 
water containing ammonia or alkali, upon 
bons-phosphate lime in a fresh state as exist- 
ing in bird dung or ammoniacal guanos. It 



72 PURE FERTILIZERS. 

may be precipitated, too, from acid solutions ; 
and at the same time some bi-phosphate of 
lime is produced. 

As prepared artificially by adding an aque- 
ous solution of ordinary phosphate of soda to 
an aqueous solution of chloride of calcium, 
it is a white precipitate only slightly soluble 
in water, but very easily soluble in acids, and 
readily taken up by water containing carbonic 
acid, ammonia, ammoniacal or even potassic 
salts. 

Some little of it is formed in my process 
for manufacturing Colombian Phosphate, as 
described in Chapter ix ; and the methods, 
described in Chapter x, produce it nearly 
pure. 

Guanos or artificial manures, which may 
contain their phosphatic element in the state 
of neutral phosphate of lime, will prove to be 
very active and potential fertilizers. 

Chemically considered, it is the best possi- 
ble material for conversion into " superphos- 
phate". The economy of sulphuric acid and 
the very high degree of soluble phosphate 
thus obtained will be great advantages to 
both producer and planter. 



CHEMICAL DATA. 



73 



Bi-pJiosphate of Lime. CaO, 2 HO, POj^ 1 18. 

This phosphate exists, naturally, only in 
small quantities, as a component of certain 
mineral waters and organic products. 

It is prepared artificially by acting on the 
tri-basic or bone phosphate of lime with di- 
lute sulphuric acid, which takes away two 
equivalents of lime, and, with two double 
equivalents of water, forms hydrated sulphate 
of lime ; leaving the phosphoric acid with 
one equivalent of lime and two equivalents 
of water, as bi-phosphate. 

To make the decomposition perfectly intel- 
ligible, it is only necessary to formulate it as 
follows : — 



One equivalent of (CaO.2HO.PO5) Bi-phosphate of Lime. 




CaO 



2SO3.2HO. 4HO. 



Two equivalents of ((2)CaO.S03.2HO.) Sulphate of lime. 



74 PURE FERTILIZERS. 

The ascending lines represent the sokible 
product, and the descending lines indicate the 
insoluble one. 

As bone-phosphate of lime consists of three 
equivalents of lime (CaO, 28 x 3=84) and one 
equivalent of phosphoric acid (P, 32 + O, 40= 
72), it follows that every equivalent = 156 
when acted on by oil of vitriol or mono- 
hydrated sulphuric acid diluted with four 
equivalents of water (2) SO3 HO (=98) + 4HO 
(=36)= 1 34, will yield — 

1. Bi-phosphateof lime(CaO(28)2HO(i8)POs(72) s 

= 118 parts by weight - - / _ 

2. Sulphate oflime (2) CaO (56) 4HO(36) 2303(80) r~^90 

= 172 parts by weight - -^ 

As much heat is generated during the 
chemical reaction, an excess of water must be 
added to provide for loss by evaporation. 
Taking this circumstance into consideration, 
then, by adding together the original items of 
the formula, the proof of the latter is made 
evident, thus : — 

One equivalent of bone-phosphate of lime= 156 by weight. 
Two equiv. of mono-hydrated sulphuric acid = 98 „ 
Two double equivalents of water of dilution= '}j6 „ 

Total - - 290 



CHEMICAL DATA. 75 

Converted into — 

One equivalent of bi-phosphate of lime = 118 by weight. 
Two equivalents of sulphate of lime = 172 „ 



Total - - 290 

This salt is very soluble in water, and its 
aqueous solution when evaporated to syrupy 
consistence crystallizes in pearly scales, which 
are deliquescent. These scales, if heated too 
long, even moderately, assume in part an allo- 
tropic condition, which is somewhat insoluble. 
By igneous fusion it wholly loses its property 
of solubility. 

Of all the phosphates of lime this is the 
favourite one for agricultural purposes, on 
account of its great solubility and consequent 
fertilizing energy. I believe, however, that 
the phosphate prepared by precipitation from 
acid solutions of animal or mineral bone- 
phosphates, and named by me Gelatinous or 
Colombian phosphate of lime, is sufficiently 
potential for producing an active and rich 
vegetation at much less cost than the super- 
phosphate. Indeed, it is more than probable 
that this latter is changed into the former by 
the carbonic acid and other chemical in- 



je PURE FERTILIZERS. 

fluences of the soil before it has had time to 
exert much action by reason of its direct 
solubility when first applied. If this does 
not take place, then much of the bi-phosphate 
would be lost by reason of its solubility ; for 
the rain would wash down into the subsoil 
all that might not be absorbed by the plants 
immediately after its application. This por- 
tion would be nearly the whole, as it is not 
rational to suppose that the vegetal absorp- 
tion could be instantaneous as to the total of 
any fertilizing element. 

If there should be any carbonate of lime, 
alumina, oxide of iron, or powdered mineral 
phosphate mixed with the pure bi-phosphate, 
as in the ordinary commercial " superphos- 
phate", the soluble phosphate of the latter is 
apt to become insoluble even in the bags, on 
account of the formation of di- and tri-phos- 
phate. When this occurs, the " superphos- 
phate" is said, in trade parlance, to ''go 
back'\ 

Precipitated Phosphate of Lime. 

This salt is said to be of the same chemical 
composition as the bone-phosphate, but with 



CHEMICAL DATA. 77 

the addition of quasi-constitutional water in 
proportion varying from four to six equiva- 
lents. It may have the formula sCaO, 
PO5 + 4HO, or sCaO, PO5 + 6H0, accord- 
ing to the manner in which it may be dried ; 
but most of this water can be expelled by 
kiln-drying. Practically considered, the cir- 
cumstances of its preparation influence also 
its composition. It is prepared always by 
precipitation with alkalies or alkaline earths, 
from solutions of the tri- or neutral-phosphate 
of lime in acids. 

My opinion is, that the precipitate com- 
prises all of the several phosphates, varying 
in proportion with the state of dilution and 
temperature of the solution and the kind 
and quantity of precipitant employed ; for I 
have certainly observed, that in its fresh 
pulpy state, it is not only very soluble in 
acetic and weak acids, but even splits into 
soluble forms under the action of water con- 
taining carbonic acid, ammonia, chloride of 
sodium, and many other saline matters. Very 
probably the carbonic acid of the soil may 
convert it gradually into bi-phosphate, di- 
phosphate, and carbonate of lime. 



78 PURE FERTILIZERS. 

In its dry state it is scarcely less sensitive, 
and these properties give assurance that 
under the chemical influences of the soil it 
will prove as potential in fertilizing as the bi- 
phosphate, and at much less expense. In- 
deed, the bi-phosphate is first reduced, doubt- 
less to the state of precipitated phosphate, 
soon after it has been applied to the soil and 
the growing crops assimilate it in that form 
through the subsequent influence of carbonic 
acid and saline associates. 

It is on account of the composite nature 
and the tender properties above noted, that I 
have not given it a place in the preceding 
chemical table, and prefer to distinguish it by 
the title of Colombian phosphate of lime, 
when it is thrown down by whiting, and Pre- 
cipitated phospJiate when ammonia is the 
precipitant. 

Sulphite of Calcium-PJwsphate, 

This is a product of the action of sulphur- 
ous acid upon tri-phosphate of lime, and its 
chemical and practical relations are given in 
chapter xvii. 



CHEMICAL DATA. 79 



Phosphate of Magnesia. 

The chemical equivalent of magnesium is 
i2"0, and it forms tri-, di-, and bi-phosphates, 
corresponding in composition with the simi- 
lar salts of lime, thus : — 

Tri-phosphate or sMgO, PO5 ; 
Di-phosphate or 2MgO, PO5, HO ; 
Bi-phosphate or MgO, POs, 2 HO. 

For all practical purposes, this salt may be 
considered as phosphate of lime, since it as- 
similates to the latter sufficiently, in chemical 
and agricultural relations, to justify the union 
of them under one head. Moreover, it is 
rarely present to any large extent in mineral 
phosphates of lime. 

Carbo7iate of Lime. CaO, CO2, = 50*00. 

Oxide of calcium (CaO) - 28"OOj or per cent. 56*00 
Carbonic acid (CO2) - 22'00 „ 44*00 



Chemical equivalent - 50'00 „ ioo*oo 

In nature, the more common forms of this 
chemical salt are the different kinds of chalk, 
calcareous spars, marbles, and limestones. 
It is very widely diffused, being an element 



8o PVRE FERTILIZERS. 



of most of the river, spring, and other waters. 
It also enters into the composition of mani- 
fold other substances to a greater or lesser 
degree. When pure, it is perfectly white. 
On being calcined at, a red heat in an open 
furnace it gives off its carbonic acid and be- 
comes caustic or quicklime (CaO). 

Carbonate of lime is insoluble in water, 
unless the latter should contain free carbonic 
acid. With this latter it forms bi-carbonate 
of lime, which is soluble. Carbonate of lime 
is also soluble in acids. It is almost an in- 
variable constituent of rock guanos or other 
phosphatic materials, but it does not impart 
any value to the latter. On the contrary, 
until the discovery of my new methods for 
the treatment of these rock guanos, it was a 
real pest, in that it consumed acid to extend 
the weight and dilute the strength of the fer- 
tilizer from those materials without forming 
any compensating product. 

According to Warrington, when carbonate 
of lime is present with phosphate of lime, 
as in mineral phosphates especially, it way- 
lays the atmospheric influences of the soil 
and monopolizes their action by its greater 



r^ 



MORFIT (III llii'.ViiniiBrliiri' nrFertifi :its 



T ~r — J _. _i 



n 



DETAILS OF ELEVATOR LIFT & PLATFORM 




t 





I'lalo 

J 1 ,-!-- 



^h 



-L.il>! H>glfa«a»T«t»t«ni.J- 



1 



CHEMICAL DATA. 8i 

chemical sensibility under the circumstances. 
Therefore the fertilizing action of the phos- 
phate associate remains dormant until the 
carbonate has been decomposed by the car- 
bonic acid of the soil. 

When the raw mineral phosphate is to be 
converted into precipitated phosphate or 
superphosphate, this carbonate of lime con- 
stituent is the first to seize and appropriate 
the earlier additions of hydrochloric or sul- 
phuric acid. 

In this way 2' 13 of hydrochloric acid (riy) 
or I '00 oil of vitriol (i'846) would be con- 
sumed by each per cent, of carbonate of 
lime. 

The profitless product thus imported into 
the resulting fertilizer would be i '29 hydro- 
chlorate of lime in the first case, and 172 of 
hydrated sulphate of lime in the second in- 
stance, according as one or other of these 
acids may have been used as the solvent. 
Hydrochlorate of lime (chloride of calcium) is 
not only an unprofitable element itself, in 
this connection, but also a deteriorating pre- 
sence, which renders the fertilizer product 

G 



82 PURE FERTILIZERS. 

hygroscopic, and depresses the content of 
soluble bi-phosphate. 

So, also, the hydrated sulphate of lime 
thus forced into the fertilizer product crowds 
out soluble bi-phosphate, and renders im- 
practicable any high strength of the latter. 

Orgmiate of Lime. 

In making a chemical analysis of a mineral 
phosphate or " rock guano", and after appor- 
tioning the lime according to its well-known 
chemical affinities, there is frequently a resi- 
due which, in our present state of know- 
ledge, cannot be allotted confidently to any 
associate element. 

I assume, therefore, until I can inform my- 
self better, that it exists naturally in combi- 
nation with the organic acids, and probably 
the silicic acid and alumina which may be 
present. 

Be that as it may, for all the practical pur- 
poses of this treatise, organate of lime is to 
be considered as carbonate of lime, and treated 
with acids accordingly, in the manufacture 
of fertilizers. 



CHEMICAL DATA. 83 



Sulphate of Lime. CaO, SO3, 2HO=86-o. 

Oxide of calcium (CaO) - 28-0, or per cent, 32-56 
Sulphuric acid (SO3) - -40-0 „ 46-5 1 

Water of constitution (2 HO) 180 „ 20-93 



Chemical equivalent - - 860 „ loo-oo 

This substance is known in nature as 
Gyp Sinn when amorphous or crystalline, and 
as Selinite or Alabaster if crystallized. It 
is white in the first, and colourless in 
the second form. It is soluble to the ex- 
tent of three parts in 1000 of water, but in- 
soluble even in dilute alcohol. Boiling hy- 
drochloric acid dissolves it more freely, 
and so also does a solution of common 
salt. By calcination at 212° to 300° F., it 
loses its water and becomes Plaster of 
Paris. 

Its presence in rock guanos neither adds to, 

nor detracts from, the value of the latter. 

Though it does not waste acid, it dilutes the 

mother-material without improving its value. 

The economy of the raw mineral would be 

better for its absence. 

G 2 



84 PURE FERTILIZERS. 



Fluoride of Calcium. CaFl = 39. 

Calcium fCa) - - 20'0, or per cent. - 5 1 "29 
Fluorine (Fl) - - 190 „ 4871 



Chemical equivalent - 39-0 „ lOO'OO 

Is known as Fluor Spar, and found gene- 
rally associated in nature with other minerals. 
It is also present in bones, to a small extent. 
Coprolites contain it, as also do some of the 
Phosphorites and Apatites. 

In its natural state it is yellowish, green- 
ish, or violet, and crystallized or crystalline. 
When heated, it becomes phosphorescent, 
and fuses at high degrees of temperature. 
Superheated steam decomposes it into lime 
and hydrofluoric acid. So, also, when fused 
with alkaline hydrates or carbonates, it is 
readily decomposed. It is itself used as a 
flux in the smelting of ores. 

It is nearly insoluble in water, but dissolves 
in very strong hydrochloric acid. When 
acted on by sulphuric acid it gives off noxious 
vapours of hydrofluoric acid, and it is on this 
account that mineral phosphates which con- 
tain much of fluoride of calcium are not a 



CHEMICAL DATA. 85 

favourite material for superphosphating pur- 
poses. It also wastes acid in the usual mode 
of operating, but in the new processes herein 
described that defect may be lessened by 
careful manipulation in the digesting opera- 
tion. Every per cent, of fluoride of calcium 
would waste 273 of hydrochloric acid of 
specific gravity riy, or 1-28 of oil of vitriol 
of 1-846. 

Chloride of Calcium. Ca CI ==55'5. 

Calcium (Ca) - - 20"Oj or per cent. - 3603 
Chlorine (CI) - - 35 "5 . „ 63-97 



Chemical equivalent - 55'5 „ lOO'OO 

Chloride of calcium is a constituent of 
numerous river, spring, and well waters, as 
also of many mineral substances. When 
pure, it is white, and so very soluble in water 
that it is one of the most deliquescent sub- 
stances known. By igneous fusion it is per- 
fectly dried ; but, on exposure afterwards, 
soon absorbs moisture. It is also soluble in 
alcohol. Its presence gives a tendency to 
humidity to those substances which contain it. 

Solutions of chloride of calcium are de- 



86 



PURE FERTILIZERS^ 



composed by solutions of alkaline carbonates 
or sulphates. With the first, carbonate of 
lime is precipitated, and alkaline chloride 
forms in solution. With the latter, sulphate 
of lime is precipitated, while alkaline chlo- 
ride remains in solution. This is effected by 
a double exchange of bases, as, for example, 
with sulphate of potassa, thus :— 

In solution. YJZ\~ Chloride of potassium. 




Ca CI. + KO SO. 




As precipitate. CaO, S0^ = Sulphate of lime. 

This property is taken advantage of in the 
new and original formulae of Chapters ix, x, 
and XI, for recovering (in the profitable form 
of ammonium or potassium chloride) the hy- 
drochloric acid used for making the solution 
of the raw phosphate. Under other circum- 
stances, the use of this acid in the manufac- 



CHEMICAL DATA, Zy 



ture of superphosphate would be less favour- 
able to the economy of the product and also 
fatal to its perfect dryness. 

Oxide of Iron. Fca 03=8o'o. 

As existing in mineral phosphate, it is most 
probably sesqui-oxide. 

Two equivalents of iron (Fe^) - 56-0, or per cent., 70'00 
Three „ oxygen (O3), 24.0 „ 30-00 



Chemical equivalent - 800 „ loooo 

In its mineral state it has only a feeble 
affinity for acids. Being thus passive, most 
of it is left undissolved, when mineral phos- 
phates which may contain it are treated in the 
cold with acids. 

Oxide of iron as well as alumina are profit- 
less constituents of mineral phosphates, both 
as to freight, expense, and fertilizing action. 
They not only waste acid but form objection- 
able compounds when the mineral is being 
converted into " superphosphate." 

Phosphate of Iron. Fcz, O3, P05= 152-0. 

As associated with the other elements of 
mineral phosphates, it is possibly in the state 



S8 PURE FERTILIZERS. 



of phosphate of sesqui-oxide ; and anhydrous. 
But, when freshly precipitated from acid so- 
lutions, it takes up four equivalents of water 
(4HO) and becomes hydrated. In this latter 
form, it differs from the anhydrous phosphate 
in important particulars ; for it is then soluble 
in water containing carbonic acid, and also in 
weak acids, with certain exceptions. The hy- 
drated, when heated to redness, becomes an- 
hydrous, and then it is only partly taken up 
even by strong acids in the cold. 

The freshly precipitated phosphate of iron, 
as above, has considerable fertilizing energy, 
more particularly when associated with ammo- 
niacal and potassa salts, as these promote its 
solubility, and the assimilation of its phos- 
phoric acid by the growing crops. 

Oxide of Alimiiniiim. AI2, 0-^=^^v\. 

In its mineral state it is generally anhy- 
drous, and not very sensitive to the action of 
acids in the cold. When freshly precipitated 
it becomes quite soluble, and even water, con- 
taining carbonic acid, takes up a portion. In 
this condition it is also completely soluble in 
solutions of caustic potassa or soda. 



CHEMICAL DATA. 89 



When mineral phosphates which may con- 
tain alumina are treated with sulphuric acid, 
the product is more or less damp, unless this 
property should be corrected by the means 
prescribed in Chapters viii and ix. 

It is also a diluting constituent of the raw 
mineral without countervailing advantages. 

Phosphate of Alumina. AI2, O3, PO^. 

The composition of the phosphate of alu- 
mina as it exists in the mineral phosphates, 
is even more doubtful than that of the phos- 
phate of iron constituent. In its natural hard 
state it is dissolved only slowly by the strong 
acids and the aqueous solutions of caustic 
potassa and soda. When precipitated from 
its solutions in acids, it is white, gelatinous, 
very soluble in acids, and more or less so in 
water containing carbonic acid and saline 
matters. When the precipitate is dried in the 
air, or by only moderate heat, these latter pro- 
perties remain unimpaired. In this latter 
condition it is serviceable for fertilization, 
upon the reasoning which has been noted 
for phosphate of iron, but in a greater degree. 



90 PURE FERTILIZERS. 

Its formula, then, is probably AI2, O3, PO5, 
9HO = 204*40, but it becomes anhydrous by 
ignition. The practical mode of converting 
phosphates of iron and alumina into fertilizers 
is described for redonda guano in Chapter 

XVIII. 

Organic Matter. 

This constituent of mineral phosphates is 
partly soluble and partly insoluble in acids. 
Most generally it contains little or no nitro- 
gen. In all cases it remains with the pro- 
ducts when the raw phosphates are converted 
into fertilizers by the processes described in 
this treatise. The action of the acids may 
modify its nature slightly, but the soluble 
portion goes with the precipitated phosphate, 
and the other forms part of the insoluble 
residue of the mineral. When the raw phos- 
phates are treated directly with sulphuric 
acid for their conversion into " superphos- 
phate," the presence of organic matters im- 
pedes the action of the acid in some degree, 
and also promotes its waste. In other re- 
spects it is merely an unprofitable diluting 
associate of the valuable components of the 
mineral. 



CHEMICAL DATA. 91 

Silica and Sand. 

These form the part of mineral phosphates 
which is insoluble in either water or acids. 
They do not waste acids ; but are, neverthe- 
less, wholly valueless in themselves, being 
inert diluents of the raw material. 

Water. 

Is nearly always present in mineral phos- 
phates as an accidental or constitutional ele- 
ment. It is not in the way, chemically con- 
sidered, but swells, unprofitably, the bulk of 
the mineral and its cost of transportation. 



CHAPTER IV. 



---ST^s-s^^ler-e-ss— 



THE GRINDING APPARATUS. 

In all extensive works the factory plant 
should comprise a grinding apparatus. But 
as such an arrangement involves the neces- 
sity of much space and a large amount of 
steam power, it is more economical, for mo- 
derate operations, to have the raw mineral 
powdered outside by a regular grinder. The 
business of the latter being a distinct branch 
of trade, I will devote a special chapter to 
the best means of practising it in connection 
with hard mineral substances. 

The usual machines for reducing the mi- 
neral phosphates to fine powder, are either 
French burr stone mills of the ordinary pat- 
tern, or cast-iron rollers like a mortar mill. 
The first are employed by certain manufac- 
turers for grinding coprolites. If the raw 
mineral should be in large lumps, it would 



THE GRINDING APPARATUS. 93 

have to be passed previously through a pair 
of iron cracker-rollers, in order to break it 
into smaller pieces, as a preparation for the 
mill. 

The Roller Mill. 

Much less expensive and more generally 
used are the cast-iron rollers. A mill of this 
construction, with rollers of eight feet dia- 
meter, will grind 200 tons of mineral phos- 
phate per week of days and nights. The 
steam-power required to drive it is equivalent 
to that of eight horses, and three or four 
labourers suffice to attend it. 

It is all-important that the rollers should 
be heavy ; and the pan may either revolve or 
be fixed. Some manufacturers prefer the 
fixed pan ; but the other arrangement is 
adopted most generally. Plate i shows a 
front elevation of a mill of this latter con- 
struction, set firmly upon a foundation / of 
mason work. The pan is b, and the crush- 
ing rollers are a a , carried by the cross shafts 
c c , bolted together in the middle. These 
cross shafts have the clips g g on them to 
keep the rollers a a in place. The pan b is 



94 PURE FERTILIZERS. 

carried by a vertical spindle d d' resting in the 
footstep p. The frame-work consists of the 
cast-iron uprights e e , the top entablature f, 
and the endstay //. The arrangement for 
motion comprises the shaft / and its plummet 
blocks 7n m , the driving pulley k, the bevel 
pinion it, and the circular rack o, fixed to the 
pan. The rollers turn round on a fixed axis 
by the revolution of the pan, and the mineral 
is kept under them by means of the scrapers. 

Some engineers construct these mills so 
that the grinding and sifting may go on si- 
multaneously in the same machine. 

Then the plan b, as shown in the drawing, 
must be made with a false bottom, upon 
which the rollers are to run. This false bot- 
tom is placed at a distance from the real bot- 
tom so as to form a chamber beneath for the 
collection of the sifted material, which passes 
through the fine holes with which the bottom 
is cullendered for the purpose. 

Or the pan may have only one bottom, and 
that cullendered, so that the material as fast 
as ground will sift through, and can be col- 
lected underneath by means of a shoot or 
otherwise. 



THE GRINDING APPARATUS. 95 

When there is no such appendage to the 
mill, the sifting must be done by a separate 
instrument, as it is necessary to have the 
powder of uniform fineness in order that the 
subsequent chemical treatment may be facili- 
tated. 

The Siftei\ 

This implement, shown in side and end 
elevation by Plate 2, consists of a strong tim- 
ber support g carrying in the interior the two 
inclined and revolving cylinders of wooden 
frame-work, shown by the dotted lines at a a 
and b b'. 

Stretching over the circumference of the 
cylinders is fine galvanized iron-wire cloth. 
The two sieves are connected by means of the 
shoot c, and derive motion from the pulleys 
d and e. The two cylinders being set in mo- 
tion by steam-power, the mineral to be sifted 
is then thrown into the end a of the upper 
one, by a man standing on the platform, b, 
formed by the framing of the machine. The 
finer portion finds its way through the meshes 
and falls into the shoot c, which conducts it 
into the end of the lower cylinder b. The 
coarser portions which will not pass through 



c,6 PURE FERTILIZERS. 

the meshes are ejected at the end a of the 
top cylinder, the meshes of which should be 
coarser than those of the lower one. In like 
manner, when the finer portion of the upper 
cylinder falls into the lower one, that part 
which is fine enough passes through the 
gauze, while the portion that is too coarse 
finds its way out at the end d' . 

It would seem, from the practical experi- 
ence of manufacturers, that the most work to 
be got out of rollers even as large as eight 
feet diameter, is ij tons of powdered mineral 
per hour. 

With all these open mills there is an un- 
avoidable loss of powder, which escapes as 
fine dust, to the extent of several or more per 
cent., in many cases, according to its density. 
I feel confident, therefore, that better pro- 
gress and economy would be realised by the 
substitution of a different arrangement; or, in 
other words, by combining the powdering 
and mixing portions of the plant into one 
consisting of a Blake's crusher and a Howel- 
Hannay mill. A sifting machine will be un- 
necessary, then, and all the loss by escaping 
dust would be prevented. 



THE GRINDING APPARATUS. 97 



A crusher is necessary to reduce the mineral 
only when it is in very hard lumps of size 
larger than an inch or two square. At all 
times, however, it will expedite the work of 
the Howel-Hannay mill, and economize the 
wear and tear of the machine to feed it with 
mineral of the size of inch cubes. 

Both of the above-named machines arc 
American inventions, but can be obtained in 
England. The Blake crusher is made at the 
Soho Foundry, Leeds, and is used extensively 
in this country. 

The Howel-Hannay mill will not only 

reduce the mineral to fine powder, but serve 

also, and even better, for powdering the 

finished fertilizer as it comes from the drying 

kiln. 

Blake s Crusher. 

This machine is shown by Plate 3, in which 
fig. I represents a front elevation; and fig. 2 a 
plan of the entire machine. 

The circle d is a section of the fly-wheel 
shaft, and the dotted circle e is a section of 
the eccentric. A pitman on rod f connects 
the eccentric with the toggles gg, which have 
their bearings forming an elbow or toggle- 



11 



98 PURE FERTILIZERS. 

joint. There is 2, fixed jaw h, against which 
the stones are crushed ; and this is bedded in 
zinc against the end of the frame and held 
back to its place by cheeks i that fit in re- 
cesses of the interior of the frame on each 
side. There is also a movable jaw j, which 
is supported by the round bar of iron k 
passing freely through it and forming the 
pivot upon which it vibrates. An india- 
rubber spring L is compressed by the forward 
movement of the jaw, and aids its return. 

The frame a (see plan, fig. 2), which receives 
and supports all the other parts, is cast in one 
piece, with feet to stand upon the floor or 
upon timbers. These feet are provided with 
holes for bolts by which it may be fastened 
down if desired ; but this is unnecessary, as 
its own weight gives it all the requisite 
stability. The fly-wheels bb are on a shaft 
which has its bearings on the frame, and 
which is formed into an eccentric between 
these bearings. The pulley c on the same 
shaft receives a belt from a steam engine or 
other power. 

Every revolution of the eccentric causes 
the lower end of the movable jaw to advance 



MORFIT 




SCALE OF FEET. 

/ 2 



3j>f ei>ilb/ d'-fti'J^ 



TViilinf.r;i- CPfkO, PDr,-.T^,rvoro,.», 



M OR FIT oil iheMamdaeliirc of'Fertiliirrs. 



DETAILS OF MIXER, IN SECTION, 




w////// / //m//////m//m , 






U ^' U "' 




J--J 



I , 



Fl C. 111. 




FlC. II. 



3j«K;i.ill>' A-.Mvjtfdioi ll^Miii1'iis"At.H;.i.;'-n l;:^ - 



SCALE OF Ft FT. 



Plat( 




.■:-.LbroalB.Dayiic..Sx-. I.it>i 



'[ ru);ii'-T 'tt. C",60. Pau-iTiDs'f!' HcA'/, 



THE GRINDING APPARATUS. 99 

towards the fixed jaw about a quarter of an 
inch and return. Hence, if a stone be 
dropped in between the convergent faces of 
the jaws, it will be broken by the next suc- 
ceeding bite ; the fragments will then fall 
down lower and be broken again, and so on 
until they are small enough to pass out at 
the bottom. The readiness with which the 
hardest stones yield at once to the influence 
of this gentle and quiet movement, and melt 
down into small fragments, surprises and 
astonishes every one who witnesses the opera- 
tion of the machine. 

It will be seen that the distance between 
the jaws at the bottom limits the size of the 
fragments. The distance, and consequently 
the size of the fragments, may be regulated at 
pleasure. A variation to the extent of five- 
eighths of an inch may be made by turning 
the screw-nut m, which raises and lowers the 
wedge N, and moves the toggle-block o forward 
or back. Further variation may be made 
by substituting for the toggles gg, or either 
of them, others that are longer or shorter ; 
extra toggles of different lengths being fur- 
nished for this purpose. 

n 2 



lOO 



PURE FERTILIZERS. 



This machine is made of several sizes. 
Each size will break any stone, one end of 
which can be entered into the opening be- 
tween the jaws at the top. The size of the 
machine is designated by the size of the 
opening ; thus, if the width of the jaws be 
lo in., and the distance between them at the 
top 7 in., the size is called lo by 7. 

The following table shows the several sizes 
of machines which are offered for sale ; the 
product per hour of each size, of fine road 
metal from the hardest materials, Avhen run 
with a speed of 250 — the power required to 
perform its duty, — the whole weight of each 
size, and the weight of the heaviest piece 
when separated for transportation. 



Size. 


Product 
per Hour. 


Power 
required. 


Total 
Weight. 


Weight of 
Frame. 


Price Nett. 


On Wheels. 




cubic yds. 


Horse. 


cwts. qrs. 


bs. 


cwts. qrs. lbs 


£ 


s. 


d. 


£ s. d. 


6 by 4 


I^ 


2i 


36 





18 


75 








80 


10 „ 7 


3 


4 


78 





37 2 


140 








147 10 


IS .. 7 


4i 


6 


108 





54 


180 








190 


%o „ 9 


6 


8 


156 





74 


240 








255 


24 ,,12 


8 


12 


376 





80 


350 








— 



The whole length of the machines (accord- 



THE GRINDING APPARATUS. loi 

ing to size) is from 4 to lo feet ; the height 
being 5 to 8 feet ; and the width 3 to 5 feet. 

The machines may be driven by any power 
less than that given in the table, and yield a 
product per hour proportionally. 

These machines may be set in one minute, 
to give the product any size from 2 inches, 
for road metal to fine gravel. 

The product of these machines per hour, in 
cubic yards of fragments, will vary consider- 
ably with the character of the stone broken. 
Stone that is ''granular ' in its fracture, like 
granite and most kinds of sandstone, will 
pass through more rapidly than that which is 
more compact in its structure. The kind of 
stone being the same, the product per hour 
will be in proportion to the width of the jaws, 
the distance between them at the bottom, and 
the speed. The proper speed is 200 to 250 
revolutions per minute, and to make good 
road metal from hard compact stone the jaws 
should be set from \\ to i\ inches apart at 
the bottom. For softer and granular stone 
they may be set wider. 

These machines can be fitted with a screen, 
as shown by fig. i, when it is required 



I02 . PURE FERTILIZERS. 

to assort the crushed stone into different 
sizes. 

The Howell-Hannay Mill. 

The mineral, having been reduced to the 
size of gravel by the crushers, is next to be 
subjected to the action of one of these centri- 
fugal mills, constructed upon the principle of 
reducing quartz, stones, fossils, and other re- 
fractory substances of a similar kind to fine 
powder by percussion — that is to say, by the 
sudden check of the momentum of a body 
moving at great velocity. To this end a 
closed circular chamber is provided, and set 
in either a vertical or horizontal plane. On a 
shaft in the centre of this chamber is mounted 
a plate or disc with arms projecting therefrom 
towards the inner periphery of the chamber, 
and this periphery, against which the material 
to be operated upon is intended to be dashed 
with great violence, is furnished with ribbed 
or angular surfaces. The material to be 
crushed is fed in at one side of the chamber 
(at the centre thereof) by a hopper, and when 
crushed it is discharged through an opening 
on the other side, the rapid rotation of the 



THE GRINDING APPARATUS. lo-- 



arms on the central shaft while dashing the 
material against the ribbed or angular sur- 
faces of the chamber, causing also a current 
of air to carry off the powdered material at 
the discharge opening. A general view and 
details of this implement are shown by Plate 
4, in which figs, i and 2 represent the side 
and end elevations of the improved machine. 
Fig. 3 is a plan of the same ; fig. 4 a side 
elevation of the machine, with one end of the 
crushing cylinder removed to show the con- 
struction of its parts ; fig. 5 is a plan of the 
interior surface of the cylinder ; fig. 6 is a 
modification of the same ; and fig. 7 repre- 
sents a section through the arms in the line 
X X oi fig. 4. A A are two supporting beams, 
on which are erected four upright standards 
B, two on either side, connected together at 
top by beams c, these being in turn connected 
and braced together by cross rails d, on which 
are secured bearings e, in which is supported 
a revolving shaft f. On one end of this shaft 
is mounted an armed disc G, and on the other 
a driving pulley h. The disc G is enclosed 
by a casing i, consisting of a cylinder j, and 
end-caps or covers k and k\ In the arrange- 



104 PURE FERTILIZERS. 

ment represented in the drawing the cylinder 
J is armed on its interior with ribs, which 
may be either of a triangular form, as shown 
in figs. 4 and 5, or formed of pyramidal 
teeth, as shown in fig. 6, or they may be 
made in any other suitable form. Instead of 
teeth the inner surface of the cylinder may be 
left smooth, but the inventor prefers to use 
the teeth. The casing i thus constructed is 
firmly and permanently secured to the frame 
of the machine by means of screw bolts a and 
nuts b. On the end k next the frame of the 
machine, and at its centre, is cut an opening, 
through which the shaft f passes, whilst in 
the outer end k* of the cylinder, and at its 
centre is cut another circular opening d, but 
of larger size, for the purpose of feeding the 
machine with the quartz or other material to 
be pulverized, for which purpose a hopper of 
suitable shape and dimensions is attached to 
the machine. At or near the inner periphery 
of the cylinder there is cut through the inner 
end or disc k of the casing i another opening, 
to which is secured a carrying tube l, through 
which is forced by the current of air engen- 
dered by the rotation of the arms, the pul- 



THE GRINDING APPARATUS. 105 

verized quartz or other substance as fast as 
produced, and by it conducted wherever de- 
sired ; or the spout may be let into the 
cylinder direct if deemed expedient. In this 
instance the arms, for the purpose of strength 
and to lighten as much as possible their 
weight, are represented as being cast on a 
disc G, which tapers from the shaft f out- 
wards, but if desired they may be cast on a 
hub, or in any other suitable manner con- 
sistent with strength, and they may either be 
made straight or curved. The disc on which 
they are cast (when a disc is used) may also 
be made in any suitable form consistent 
with the purpose for which it is intended 
to be used. On the inner surface of the 
cylinder ribs or teeth are formed, having the 
plane of their face set at right angles to the 
direction of the quartz or other substance as 
it is projected from the beaters or arms, under 
which circumstances they may either be made 
to run straight across the cylinder, as in fig. 
5, or be cut somewhat of the form represented 
in fig. 6, so that the whole momentum of the 
quartz or other substance may be checked at 
once. As to the arms themselves, they may 



io5 PURE FERTILIZERS. 



be set at such angle to the shaft, and made in 
such form, curved or straight, as may be 
found best adapted for the most perfect 
execution of their work. In order to make 
the casing of the arms perfectly tight and 
strong, the ends or caps k k' are made to fit 
tightly over its ends, and the whole is then 
bolted firmly to the frame, and if deemed 
expedient for this purpose, a strip of lead, 
india-rubber, or other suitable material may 
be inserted between them. 

The operation of the machine is substan- 
tially as follows. The quartz or other mate- 
rial, broken to a suitable size, is fed in by hand, 
or by means of a hopper, through the open- 
ing in the outer cap k, when it is driven with 
great force and velocity by the arms or beater 
c of the disc g against the cylinder j, toothed 
or otherwise, and there reduced to powder, 
such parts as may not have been completely 
pulverized rebounding back, and being again 
projected by the arms against the cylinder 
until perfectly reduced. The pulverized ma- 
terial is carried and discharged by the cur- 
rent of air engendered by the rotation of the 
arms (or by other means suitably arranged 



THE GRINDING APPARATUS. 107 

for that purpose) through the tube l, and by 
it conducted wherever desired. If required, 
the cylinder j may be made to rotate to in- 
crease the speed in the opposite direction to 
the arms, in which event the machine would 
require to be suitably constructed for that 
purpose. It may be driven by a number 19 
pulley. The frame of the machine is repre- 
sented as being made of wood, but it may be 
of iron. The rest of the machine is made of 
iron, the face of the arms and teeth being 
chilled. 

To render this machine effective, it must 
be rotated with great velocity, say from one 
to two thousand revolutions per minute, ac- 
cording to the diameter of the machine ; and 
for this purpose a power of twelve to fifteen 
horses is required. 

The cost of a machine complete is from 
^80 to ^100. 



CHAPTER V. 



THE PLANT. 



A PLANT for the manufacture of fertilizers 
comprises numerous pieces, each of which 
should be constructed and arranged with a 
view to durability and facile management. 

Manual labour being a capricious, and 
time an important element of cost in evolving 
the products, this consideration is indispens- 
able to the economy of their manufacture. 

In other words, the apparatus must be 
made throughout of the best materials and 
w^orkmanship, so as to save oft-recurring out- 
lay for repairs, and also be as nearly auto- 
matic as possible in order that it may move 
by steam-power, and do work quickly with 
the least possible personal attention. 

The pieces about to be described are those 
of general utility, and which constitute the 
actual requirements of a proper equipment. 



THE PLANT. 109 



The supplementary apparatus pertaining to 
special processes will be set forth in their 
proper places. 

The Steam Boiler and Engine. 

The power of these implements must be 
according to the amount of work which they 
are to do. In all cases, however, it is much 
more economical and convenient to have 
them rather above than below the exact ca- 
pacity which may be required. The expense 
of a large boiler is very much less, propor- 
tionally, than that of a small one 

Boiler power of 40 to 60 horses is a none 
too liberal allowance for a large factory which 
may require much steam for other purposes 
besides driving the engine. Even for a manu- 
factory of moderate extent the boiler should 
be of 25 horse-power, and the engine of 12 
to 15 horse-power. 

In all cases, a smoke-consuming arrange- 
ment should be attached, so as to facilitate 
the burning of the fine and cheap coal dust. 

The Roasting Furnace. 
This is a reverberatory furnace with a 



no PURE FERTILIZERS. 

broad bed for roasting those mineral phos- 
phates which may contain sulphur, pyrites, 
and much organic matter. Its position is 
shown at p on the ground-plan, plate i6. 
The preparation of the raw phosphate in this 
manner economises acid and saves time as 
well as labour in the subsequent operations. 

A furnace, i6 feet long and 13^ feet broad, 
with an arch of the mean height of 2 feet 
from the bed, will have the capacity for 
roasting three tons of raw mineral at each 
charge ; and four to six charges may be com- 
pleted in twenty-four hours. 

The Platform and its Accessories. 

This arrangement is shown by Plates 5, 6, 
and 7, and comprises a platform, an elevator, 
a lift, an acid reservoir, and a mixer. 

In the drawings, which are actual construc- 
tion plans to a scale, the side walls of the 
buildings are shown at a a, and the roof at 
B, c being a floor for the convenience of the 
workmen. 

The platform is seen at d, and is a strong 
timber work supporting the acid reservoir v 
and the mixer b, in connection with the ele- 



fstpuf 



i 



% 



^ 



1^ 



I- 



o 



o 

en 

a: 
o 

cc 

ul 

I- 
CO 

Ul 

o 



l-l 
<l 
> 

LlJ| 
_l 

Ld 



< 

Q_ 



o 



y. 



MORFIT cm the ManiilacKirv orFcrtiUxcr.s 



Digester or Solution Vat 

1, 



Fig I 




^ 



ElEV AT 1 N. 




ScoLE OF Fee 



iii&ei fcf K Uorfita Wiidi n rernll2=! 



THE PLANT. in 



vator a a a and the cage u, which brings up 
the carboys of acid to the reservoir. The 
vertical guides for this lift are shown by / / /, 
and the gearing to hoist it by w w. The 
gearing x works the elevator, and the main 
shafting y hung to the roof of the building 
drives all the machinery. 

The platform o should be enclosed by a 
strong railing to prevent accidents ; and com- 
munication between the ground floor, it, and 
the floor c, must be established by means of 
a stairway with broad steps. 

The Elevator. 

This is to carry the powdered mineral from 
the floor to the mixer b. It is an endless 
flexible belt a a passing over a pulley at each 
extremity. A screw arrangement is for in- 
creasing the tension of the band in case this 
latter should become slack. Motion is com- 
municated by the counter shaft x driven from 
pulley on main shaft y. 

The belt being put in motion, dips up the 
powder from the floor beneath by means of 
the galvanized iron scoops or cups n n ii, 
\\hich, as they return downwards, drop it into 



112 PURE FERTILIZERS. 

the hopper of the mixer b, where it meets the 
diluted acid, issuing in a graduated stream at 
the same time from the reservoir v. At this 
moment the powder and liquid are thoroughly 
intermingled by the revolving spindle of the 
mixer and its blades preliminaiy to passing 
down by gravitation through the shoot c into 
the stone vats beneath. 

The Lift. 

The lift is for hoisting the carboys of acid 
to the tank or reservoir v. It is fixed to the 
rear of the platform, and consists of two 
cages u ti, sliding between strong vertical 
guides / / /, and worked by the gearing w w, 
driven direct from pulley or main shaft y. 

While one is taking up the full carboys, 
the other is carrying down the empties. 

The reducing gear w w serves to diminish 
the speed and increase the power derived 
from the main shaft ; and there are three 
pulleys, one narrow and fast, and the other 
two broad and loose, driven from the main 
shaft by one open and one cross belt. By 
shifting the position of these belts, so that 



THE PLANT. 113 

one or the other is upon the narrow pulley, 
the motion is reversed. 

The whole of this driving- arrangement is 
fixed conveniently to beams carried by the 
roof of the factory building. 

When dilute acid is to be used, it must be 
first emptied into a reservoir in the ground 
beneath, and thence pumped up by means of 
a pump constructed of lead and gutta-percha. 
This more convenient mode of hoisting is 
less applicable to strong sulphuric acid, which 
should be raised in carboys. 

So also hydrochloric acid, on account of 
its corrosive qualities, must be raised in car- 
boys or by means of the monte jus. 

The Acid Reservoir. 

This is a tank for holding the charge of 
acid which may be required for an operation. 
It consists of a wooden case v, lined with 
lead for sulphuric acid, and coated, inside and 
outside, with stearic pitch for hydrochloric 
acid. Such linings are necessary as protec- 
tion against the corrosive action of the acids. 

There should be two adjoining. The tops 

of the reservoir are level with the cage it at its 

1 



114 



P URE FER TIL IZER S. 



highest point, so that when the lift brings up 
the carboys they may be moved readily on 
top of V. Then they are turned over, with 
their necks in the charging hole, so as to 
avoid any escape of fumes. As soon as a 
carboy is emptied, it must give place to a 
full one, until the reservoir is charged. The 
acid is drawn from the reservoir by means 
of a stone-ware tap. A suitable one, with 
bracket for fixing it in any convenient posi- 
tion, is made by Barnett, of Hoxton, Lon- 
don, and shown by figs, i and 2. The 
tall stem A is a pipe of lead or hard vul- 
canite connected with the acid reservoir, for 
the passage of the acid ; but a glass or vul- 
canite ball D, upon which a regulated pressure 





FiL'. I. 



Y\\^. 2. 



THE PLANT. 115 

' a, _ 

is applied by means of the screw and handle 
c, lessens or stops the flow, as required. 

By turning the handle so as to loosen the 
screw, the pressure of the acid forces up the 
ball D, and the liquid passes through the 
outlet F. In like manner by screwing down 
the ball, the outlet is closed. The packing e 
is made of felt. 

The body b of the tap may be made of lead, 
vulcanite, or stoneware, according as the 
tap is intended for the use of sulphuric or 
hydrochloric acid. 

This form of tap is not only cleanly and 
convenient, but very much less liable to be- 
come loose than any other kind. 

It were better to avoid the use of metallic 
nails in the construction of this reservoir, on 
which account the joints should be dovetailed 
and fastened with marine glue. The planks 
should be an inch and a half thick, and to 
give strength to the whole it must be bound 
with wrought-iron hoops or bands held tight 
by a coupling-screw arrangement at the ends. 

The Mixer. 

This is a wooden box, painted inside and 

1 2 



ii6 PURE FERTILIZERS. 



outside with the protecting pitch already 
mentioned. It is shown in place by b, Plates 
5 and 6. A sectional view of its details is 
presented by Plate 7, and the description 
which follows will be in connection with this 
latter drawing. 

The sides of the box are f f, and fitting 
into the top of this box is the hopper e, which 
receives the powdered mineral as it falls from 
the scoop cups c of the elevator. The acid 
enters the mixer at the base of the hopper e, 
through the wooden pipe t, coated internally 
with the protecting pitch just prescribed, and 
connected with the reservoir. The fast and 
loose pulleys l, drive the spindle d, which 
carries the blades. 

The spindle g, of the mixer, is made of very 
hard and tough wood, and has four blades 
H H, passing through it. They are set at 
right angles to each other and at an angle 
with the axis of the spindle, as shown at 
h' h'. By this means they move like a screw, 
and force the mixed mass through the pass- 
age I, into the collecting-box, whence it 
passes through the shoots n n, into the vats 
or receptacles beneath. This collecting-box 



THE PLANT. 117 



may be omitted, and then the wet mass will 
fall directly from the mixer into the vats. 
The number of diverging shoots should cor- 
respond with the number of vats to be fed, 
and each one must lead into its special vat or 
receptacle. 

The passage from the hopper to the mixer is 
seen at m ; and a semi-circular wooden valve 
p, working on a spindle R, closes the open- 
ings of the shoots at will. These are better 
shown in fig. 3 (Plate 7), which is a plan 
of the collecting-box, with its top removed to 
expose the valves p p p P', of which two (p p) 
are represented as closed, and two (p p) as 
open. All the parts should be covered with 
a protecting coating of the stearic pitch. 

The Digester or Solution Vat. 

The next implement to be installed is the 
stone vat in which the raw mineral is to be 
acted upon by the hydrochloric acid. It is 
shown by Plate 8 as constructed of flag- 
stones ; but any other material will answer 
which is proof against the action of acids. 

It is placed on the ground in advance of 
the elevator, and should constitute one of a 
row or series of ten. 



ii8 PURE FERTILIZERS. 

The drawing shows the whole arrangement 
in front, elevation and details. 

The form is that of a square box a, 
mounted upon a support of mason-work b, 
which rises from the ground about i8 
inches. Each of the ends and sides, as well 
as the bottom, must be of an entire piece of 
stone without crack or fault. The bottom 
piece is large enough to cover the whole sur- 
face of the support b, which extends i6 
inches beyond the circumference of the vat, 
in order to form a broad base c. 

The bottom piece c, is to be thicker than 
the sides and ends b c, and these latter are 
set into the former by means of a nicely- 
fitting groove cut around at about 12 inches 
from the circumference. In like manner, the 
ends are adjusted to the side-pieces by means 
of similar grooves in proper places. 

The front and back sides c c\ are 4 inches 
larger than the ends, in order to be grooved 
for receiving these latter. All the joints are 
first sealed with Portland cement or plaster 
of Paris, and then covered with a layer of 
stearic pitch. The whole is held firmly to- 
gether by the strong iron bands d d, with 
screw-nut ends c e. 



THE PLANT. 119 



The bottom stone is 7 feet 8 inches square. 
The side and the end pieces have each a 
height of 4 feet ; but the length of the 
former is 5 feet 4 inches, while that of the 
latter is only 5 feet. This gives a clear ca- 
pacity of about 100 cubic feet to the vat, 
which is sufficient for the treatment of one 
ton of raw mineral and upwards at each 
operation. 

Surrounding the vat proper, and built up 
2 feet from the base c, is a brick wall d, 
forming an enclosure of 4 inches diameter 
throughout, to act as a hot-air chamber e. 
This brick enclosure is to be capped with a 
thick flag-stone f, laid level, and kept firmly 
in place by means of cement and iron screw- 
bolts set into the brick-work. 

In the air-chamber, and surrounding the 
stone vat, is a circuit of iron tubes yy^ for the 
circulation of a current of steam, in order that 
heat may be applied during the process of 
digestion. These tubes should be coated on 
the outside with a thick priming of oxide of 
iron paint, and then with a layer of stearic 
pitch to prevent rusting. 

Each vat is fitted with a cover made of cast 



I2P PURE FERTILIZERS. 

iron plate and protected with paint and pitch, 
as just mentioned. To facilitate its move- 
ment it is hung upon pulleys, as shown by 
g, //, i, with the handle of the chain in reach 
of the workman, and high enough to allow 
convenient stirring of the contents of the vat 
as may be necessary. 

At the rear of the wall and coinciding with 
the top F of the air-chamber, there is a strong 
wooden platform g, to facilitate the stirring 
of the contents of the vat and removing re- 
fuse matter. 

The surrounding hot-air chamber of the 
vat may be dispensed with, and the whole 
structure reduced to a simple stone box by 
incurring some extra expense in the first in- 
stance for platinum heating tubes a a, figs, i 
and 3 of the Plate. They should dip directly 
into the contents of the vat, and are therefore 
adjusted by a screw-coupling attachment g g, 
to the steam-fed pipe o, above the vat. To eco- 
nomize the expense, the lower parts h, of the 
platinum tubes need only be 30 inches long, 
as the parts r, above the coupling, are iron 
elbows. These tubes are made by Benham 
and Froude, Chandos Street (W.), London. 



THE PLANT. 121 



A tube of li inches diameter, and sufficiently 
stout for this purpose, will weigh 14 penny- 
weights to the running inch, and cost 17s. 6d. 
for that length, or ;^io los. per linear foot. 

Plain iron tubes, covered inside and out- 
side with hard vulcanite, as prepared by Cow, 
Hill, and Co., Cheapside, London, may be 
made to serve in place of those from platinum, 
but they require more care in the handling. 
These hard India-rubber coverings will resist 
the strongest hydrochloric acid, either hot 
or cold, and even hot oil of vitriol. Steam 
heat softens them so slightly as not to affect 
their usefulness in any great degree. 

The weight of the vulcanite coverings 
w^ould be four pounds or less per running 
yard, and their cost about 3s. Qd. to 4s. per 
pound, including workmanship. 

Porcelain-lined iron tubes, when the en- 
amel is free from lead, arsenic, antimony, or 
other ingredient which may render it destruc- 
tible by acids, or easily worn away, are very 
excellent substitutes for either of the preced- 
ing. They are both cheap and cleanly. T. and 
C. Clark and Co., Wolverhampton, manufac- 
ture this kind of ware in very superior quality. 



122 PURE FERTILIZERS. 

The direction of currents of steam imme- 
diately into the vat affords facility of regu- 
lating the temperature of the digestion and 
rousing the contents by a ''blow up", as may 
become expedient or necessary. 

As platinum resists the action of acid, 
there is no wear and tear of these tubes, and 
the expense of using them is only the annual 
interest on their first cost. 

These screw-coupling attachments allow 
them to be moved at will, and thus two or 
four tubes may be made to serve for heating 
and stirring a series of twelve vats. 

The charging of the vat with the materials 
for a digestion is done in two ways according 
to circumstances. When the powdered mine- 
ral and acid are to enter in a mixed, moist 
state, the vat must be charged by means of 
the lift elevator and mixer (Plates 5, 6, and 
7). On the other hand, if the materials are 
to go in separately, the charging is more 
conveniently effected from the platform g, 
Plate 8. 

To charge the vat from this platform with 
acid, the latter must be brought in carboys 
to the side upon a trolley (Plate 9) of wood. 



THE PLANT. 123 

The platform of this trolley corresponds in 
height with that of the vat. 

The Syphon. 

The liquor of the vat, when clear, is drawn 
off from the settlings or insoluble residue, by 
means of a syphon ; because it is inconve- 
nient to fit taps to the sides of a stone vat. 
The most convenient form of this apparatus 
for large operation with acid liquors, more 
particularly when hot, is that designed by 
Mr. Harrison Blair, and shown by fig. 3. 

It consists of an iron tube, bent in the 
usual form, and with one leg longer than the 
other, but at the highest point of the arch 
there is a projecting tube which connects 
with a circular tight box a. To the lower 
part of this box is fitted an India-rubber 
tube, at the other end of which is a bucket b. 
The syphon being set with its short leg in 
the clear liquor of the vat, so as not to dis- 
turb the settled solid matter, and having its 
longer leg dipping into the liquid contained 
in the trough which is to lead the filtrate 
liquor away into a separate vat, the bucket is 
then to be filled with water and raised above 



124 



PURE PER PIL IZER S. . 




Fig- 3- 

the level of the box a. The water naturally 
passes then from the former to the latter; but 
now, on lowering the bucket b, it returns, 
forming a partial vacuum in a, and the air 
is drawn out of the syphon. This arrange- 



THE PLANT. 12 = 



ment is at once clean, convenient, and suit- 
able for acid solutions, whether hot or cold. 
Moreover, it is without risk to the workman. 

The Monte-Jus. 

When the solution liquor has been drawn 
off by the syphon from the digestion vat into 
the reservoir in the ground, it requires to be 
mounted into another vessel for the next 
operation. The reservoir is constructed, 
therefore, as a monte-jus. 

This piece of apparatus is substituted for 
pumps whenever the liquor to be raised 
from the lower to an upper vessel is too 
bulky or too corrosive to be pumped up. Its 
arrangement is shown by Plate 10. 

For this purpose, it may be made of cast 
iron as to the reservoir part s, and the top t. 
This reservoir is a mere round cylinder, with 
its top and bottom fitted to it by means of 
screw-bolts and india-rubber washers, so as 
to form air-tight joints. Before it is set into 
the ground its whole exterior and interior 
must be primed and coated first with oxide 
of iron paint and then with stearic pitch. 

At the top there is an iron tube c, protected 



126 PURE FERTILIZERS. 

as above, or, better, lined with gutta-percha, 
for conveying the liquor of the digestion-vat 
from the tube-gutter into which the syphon 
drops it. 

The exit pipe A, similarly constructed, de- 
livers the contents of the monte-jus wherever 
it may be directed. 

In order that the confined air may escape 
when the monte-jus is being filled, there is a 
vent tube f. 

As just explained, the reservoir is charged 
through the tube c, and when nearly full the 
taps c' and f' are closed so as to form a her- 
metic chamber. The air-pump attached to 
the pipe d is then set in operation, so as to 
compress the air above the fluid in the closed 
chamber s. The tap on the end of the tube 
A being then opened, the fluid mounts and 
passes on to its destination, under the pres- 
sure thus applied to its surface. High pres- 
sure steam may be used instead of the com- 
pressed air of the air-pump. 

These implements as well as pumps are 
made by the engineers who do the work for 
soda manufactories. 

Gutta pcrcha and other kinds of pumps 



THE PLANT. 127 

for mounting acids are made by A. Lerverd 
et Cie., 218, Faubourg St. Martin, Paris; W. 
Neill and Sons, Bold, St. Helen's Junction, 
Lancashire ; and John Cliff, Runcorn, Eng- 
land. 

The Precipitation Vat. 

This is the vessel into which the monte-jus 
delivers the acid solution, in order that it may 
be treated with a precipitant for the recovery 
of the phosphates which it has dissolved from 
the raw mineral. It is placed upon a strong 
base, at an elevation of twenty feet,* so that 
its contents may be drawn off when required 
through taps and gutters, by natural descent, 
into the receiving vessels beneath. There 
should be a pair of them at least. Plate 1 1 
shows this vessel a as resting upon its brick- 
work support B. It is a large rectangular box 
made of thick wooden planks, and bound 
round with wrought-iron clamps d. These 
clamps or hoops are joined at the ends by a 
screw arrangement, fig. 3 of the Plate, so that 
they may be adjusted tightly by a nut connec- 

* By a mistake, the drawing (PI. 11) shows this base to 
be only two feet. 



128 PURE FERTILIZERS. 

tion. Behind and near the bottom is a small 
manhole of about six inches diameter, as an 
outlet for the solid precipitate. Above it, but 
in the front of the vat and at a distance of ten 
inches apart, are other openings, bb bb, fitted 
with tampons, c c c c, for drawing off the 
supernatant liquor as may be required. 

The plug portion of the tampon is made of 
india-rubber, and has a hole through its centre 
in order that it may pass over the end of its 
handles. This latter is a wrought-iron rod 
with a screw cut and nut at the lower end for 
fixing the indiarubber plug tightly in place. 
Fig. 4, Plate 1 1, shows the tampon separately. 

Though it is not absolutely necessary for 
this vat to have a protecting coating, it would 
be better to paint it over with the stearic 
cement aforementioned, as acid liquors injure 
wood sooner or later. 

The heating and stirring of the contents 
are accomplished, when required, by means 
of steam-currents. For this purpose there 
are tubes s s s, dipping into the vat. They 
are attached by coupling-screws to the feeder, 
which is a large tube a, leading from the 
steam-boiler of the factory, and firmly fixed 



THE PLANT. I2g 



to the wall at the rear of the vat, and just 
above its top. The smaller dip-tubes s s s, 
are made movable because they require to 
be cleaned frequently of the rust which may 
form on them ; but the better way would be 
to have them porcelain-glazed on both inner 
and outer surfaces. 

An enlarged view of the coupling-arrange- 
ment is shown by fig. 5, Plate 11. 

This precipitation vat will serve very well 
for all ordinary operation, but in cases where 
it is desired to wash the precipitate wholly 
free from its mother liquor, and rapidly, then 
it would be expedient to employ one of the 
two forms of apparatus (Plate 17 or 22) de- 
scribed for special purposes in Chapters viii 
and XIV. By means of their vacuo-filter 
arrangement a large volume of precipitate 
may be cleaned in a short time. 

T/ie Drying Kiln. 

These kilns, shown by Plate 12, are in 
pairs generally, and should adjoin the eva- 
porating pan, in order that the contents of 
the latter may be drawn into them conve- 
niently, when required. They are to give the 

K 



I30 PURE FERTILIZERS. 

final drying- to the precipitate when it is to be 
sent into the market, either as precipitated 
phosphate, Colombian phosphate, or Colom- 
bian fertilizer. The pulp from the precipita- 
tion vat is led directly into the kiln by means 
of a movable connecting gutter. Fig. i on the 
plate shows a sectional elevation of this kiln. 
Its form and construction are much after those 
for drying white lead. The basin portion is 
about 12 inches deep, and should be w^ell 
lined with the best hydraulic cement and a 
coating of plaster of Paris. The bed of the 
basin, as well as the furnace portions, are to 
be built of smooth fire-tiles and bricks. 

In order that the heat may be distributed 
uniformly, so as to insure a moderate tem- 
perature, the flues are arranged as shown by 
fig. 2 on the plate, which is a sectional plan 
along the lines a and b. 

The IVash Vat. 

This vessel is that in which the liquor 
from the precipitated phosphate is drawn, 
and therefore it must be placed with its top 
below the level of the bottom of the precipi- 
tation vat. This position allows the liquor 



THE PLANT. i;i 



of the upper vat to be drawn into the lower 
through taps or by means of a syphon, with 
the least possible delay and labour. It is the 
exact counterpart in all other respects to the 
precipitation vat, described at page 127 ; that 
is, it is constructed of the like material and 
has corresponding dimensions. There should 
be a pair of them, side by side, or rather end 
to end. 

The Evaporating Pan. 

This may be made either of steel-plate, 
cast-iron, or sheet-lead, and is usually set 
W4th a duplicate. They receive the clear 
liquors which are drawn off from the precipi- 
tation and solution vats, in order to concen- 
trate them to the crystallizing point or eva- 
porate them to dryness. Plate 13, fig. i, 
shows a range of these pans: a being the pan 
portion, b the fire-door, c the ash pit. The 
whole is supported by masonry, that part 
where the front of the pans rests being a 
dome of fire-brick. 

The steel pan is almost 18 inches deep. 
The manner in which the flues are to be built 
is explained by fig. 2, Plate 13: b being the 

K 2 



132 PURE FERTILIZERS. 

fire-grate of the furnace, and a' a' a the brick 
walls, which form the channels for the distri- 
bution of the current of heat throughout the 
bottom of the pan which rests upon them. 

If the pan is of sheet-lead there must be an 
intervening iron plate between it and the top 
of the walls a' a' a', both as a support and 
protection for its bottom. 

An iron stairway affords the facility to the 
workman of mounting to the top of the pan, 
as may be necessary for observing the opera- 
tion and attending to it. 

Mixing Machines. 

When the fertilizer prepared by either of 
the processes hereinafter described, has 
reached the dry state, it is more or less 
lumpy ; and for the purpose of reducing it to 
powder of uniform fineness, and frequently 
also of associating it with other substances, 
it must be passed through a mixing machine. 
The comparatively loose texture of the mass 
renders this operation both simple and rapid 
with a suitable implement. 

The machine in most general use, and 
which does its work, very satisfactorily, is 



THE PLANT. 



oj 



that known as Thomas Carr's Patent Disin- 
tegrator, made by the inventor at Bristol, 
England. My opinion, however, is that the 
Howel-Hannay centrifugal mill, already de- 
scribed and recommended in Chapter iv for 
powdering the raw mineral, will serve at the 
same time, and most advantageously, all the 
purpose of a mixer. Such a utilization of 
one machine for several different operations 
will therefore promote economy of both plant 
and space. The Howel-Hannay machine 
prevents all loss by escaping dust, and makes 
a powder of great fineness, whilst that of 
Carr produces a granular powder. 

Carrs Disintegvator. 

This apparatus is the invention of a gentle- 
man who has become distinguished for his 
practical genius in mechanical engineering. 
It is shown in two views by Plate 14; fig. i 
being a section elevation of side, and fig. 2 a 
front elevation, with front plates and front 
standard (a) removed. 

The iron disc b, cast in one piece with a 
tube b , which works on a wTought-iron shaft 
r, carries the wrought-iron or steel rods 



134 PURE FERTILTZERS. 

a% which connect it with the annular disc a\ 
About a dozen of these rods are made longer 
than the others, and fasten the cast-iron disc 
a, which carries a second series of bars re- 
volving" in the same direction as the first. 
Connected with this is also a series of breakers 
a^ and d fixed at their extremities by the 
ring d' . These latter are of a strong flat 
section, and serve to break the larger lumps 
which would not pass, otherwise, through 
the bars of the cage. 

The cast-iron disc c' firmly keyed to the 
main shaft c, and driven by the pulley b\ re- 
volves in a direction contrary to the one just 
described, and carries two series of bars a\ 
secured at their extremities by rings. 

The hollow shaft b', working on the solid 
spindle c, is retained in proper position by 
means of the bearings at each extremity. 
As to this part, b^ represents two blocks of 
gun-metal bored to fit the shaft, and secured 
by means of the cup b and nut and bolt b\ 

The solid shaft runs at each end in gun- 
metal bearings of ordinary form, carried by 
the standard a, cast in one piece, with the 
bed-platc A. A casing of wrought iron a', en- 



THE PLANT. 135 



closes the whole for the purpose of confining 
the pulverising material. As it is thrown off 
radially from the machine, the wooden sides 
y y of the casing are made almost to fit the 
larger disc. 

A perspective view of the machine in place 
is shown by Plate 15, which exhibits the 
method of feeding it, and also the arrange- 
ment of the driving-belts ; that one of these 
latter on the fixed spindle being open and 
the other crossed, so as to give an opposite 
direction to each series of rings. 

The machine represented by the plates is 
that known as the '' new improved 4 feet 6 
inches size\ which costs, complete and includ- 
ing patent licence, ;^i2o: 10. 

The inventor explains the construction of 
his disintegrator, and the mode of managing 
it, as follows : — 

" It simply consists of a series of four 
strong cylindrical iron cages, of various sizes, 
formed of bars with open spaces of from 3 to 
4 inches between them, arranged concentric- 
ally one within another, around or parallel 
with the shafts or axles, and rotated therewith 
with extreme rapidity (from 350 to 450 revo- 



i:;6 PURE FERTILIZERS. 



lutions per minute), in contrary direction to 
one another, by means of an open and a 
crossed strap ; the first and third cages rota- 
ting to the right, and the second and fourth 
to the left, so that, while there are only two 
motions in reality, yet from the way in which 
the cages intersect one another, there are re- 
latively four. 

" The material is thrown in at the central 
orifice either by shovels or elevators, and after 
the lumps, if very large, are broken by a 
stationary knife (fixed so that its blade may 
extend into the interior of the innermost 
cage, but never used with very hard mate- 
rials), they are thrown out by centrifugal force 
from the first cage at a tangent to its circle, 
precisely as stones are hurled from a sling, 
and at a speed equivalent to that at which 
the beaters of the said cage are rotating 
(which is usually 50 feet per second) ; when 
meeting the beaters of the next cage, moving 
in an opposite direction, usually at 60 feet 
per second, a collision ensues similar to that 
which takes place between a cricket ball and 
bat, the shock thus produced being com- 
pounded from the aggregate speed of the 
beaters, and the speed and weight of the ma- 
terial meeting them. The projectile impetus 
of the flying material is thereby arrested, and 



THE PLANT. 137 



a fresh impulse given to it in an opposite 
direction, to meet the beaters of the third 
cage, travelling the reverse way; and so on in 
like manner with the fourth one, when, if the 
material is of a friable and non-fibrous nature, 
it is shattered by these successive blows into 
a fine granular powder usually like that of 
gunpowder, and in less than a second de- 
livered in a radiating shower at a tangent to, 
and from every portion of, the periphery (like 
coruscations of the fire-work known as the 
* Catherine wheel'), and then arrested in its 
flight by an external casing of wood or iron 
enclosing it, and usually formed like the 
paddle-box of a steamer. 

''The power required for the 4 feet 6 inches 
size varies from 8 to 10, 12, and even 14 and 
16 horse, according to the following circum- 
stances : First, the gross weight of material 
to be operated on per hour ; secondly, its 
hardness, tenacity and specific gravity; thirdly, 
the degree of fineness to which it has to be 
reduced ; and, fourthly, the speed which must 
consequently be maintained to accomplish 
the results required; for, as these four consti- 
tute, individually and collectively, a certain 
amount of work done in a given time, the 
power to execute the same must necessarily 
be proportionate thereto, as an adequate 



138 PURE FERTILIZERS. 

effect can result only from an adequate 
cause. 

** The average speed that the 4 feet 6 inches 
machines are driven at varies with the above 
circumstance, from 300 to 400, 500, and even 
600 revolutions per minute. Where, however, 
the engine is deficient in power for the work 
it is required to do, and it is desirable to in- 
crease it by working to the best advantage, 
great care must be taken not to multiply the 
speed of the disintegrator too much against 
the engine, in proportioning the respective 
sizes of the pulleys, or the engine will be 
overloaded by the adverse leverage it has 
thus to contend with, and will therefore not 
be able to attain its proper speed; whereby its 
power (deficient as it was to start with) will 
be still further diminished instead of in- 
creased. For the faster the engine runs the 
more cylinders full of steam (or what amounts 
to the same thing, the more cubic feet of it) 
it uses per minute, and therefore the more 
power it gives out in the time ; — provided, of 
course, the boiler is large enough and has 
sufficient grate and heating surface to con- 
sume sufficient coal and generate sufficient 
steam to keep the engine running at an in- 
creased speed without diminishing the pres- 
sure of the steam. 



THE PLANT. 139 



*' In driving the disintegrator it will be 
necessary to have an intermediate shaft, be- 
tween the engine and it, for the purpose of 
sufficiently augmenting the speed. This in- 
termediate shaft should be about 31 inches in 
diameter, and if driven by straps from the 
engine or its lay shaft, it should not be imme- 
diately above or below it, nor yet directly 
above or below the shaft of the disintegrator ; 
for, as the weight and sway of a long strap 
Avhen it partly rests on both pulleys are of 
great importance in preventing slipping, it 
follows that the more the shafts are on a level 
with one another the better ; otherwise the 
lower pulleys will lose the benefit of this 
weight, which is specially awkward if it hap- 
pens to be the smaller one. It would do, 
however, well enough, if a string, stretched 
from shaft to shaft, made an angle of about 
45 degrees with the horizon, and, if convenient 
to make it more level than that, so much the 
better. 

*' The intermediate shaft should also be a 
good distance apart from the shaft by which 
it is driven, and also from the disintegrator 
it drives, in order to give ample length for 
the straps ; for short straps are very objec- 
tionable, especially when there is a great dis- 
proportion in the sizes of the pulleys : the 



140 PURE FERTILIZERS. 

large pulley keeping a short strap at too wide 
an angle for it to embrace sufficiently the 
circumference of the small one, and give it 
proper hold on it, whereby it is liable to slip, 
thereby heating the machine, wearing itself 
out, and frequently flying off unless kept very 
tight, which is troublesome, and entails addi- 
tional friction on the bearings. The follow- 
ing example will give a sufficient idea of 
what is suitable. — If the pulley on the engine 
shaft is about 4 feet diameter, driving one 
on the intermediate shaft 2 feet diameter, it 
would be sufficient if these shafts were about 
9 or 10 feet apart; and if the two other pulleys 
on the intermediate shaft were also each about 
4 feet diameter, driving the small pulleys on 
the disintegrator ; then, as the difference in 
the sizes is here greater, from 11 to 12 feet 
between the intermediate shaft and the disin- 
tegrator is advisable, and if a foot or two 
more in both cases so much the better. 

" The pulleys will, of course, have to be 
proportioned to the speed of the engine, so 
as to multiply it as many times as is re- 
quired to give the disintegrator its proper 
speed ; only it is advisable that the smaller 
pulley on the intermediate shaft, that is 
driven from that on the engine, should be 
at least half as large again as those on 



MORFIT on the Jlff/iri/actarp nf'Fr?tLUr^cj's. 




JL'/' - 1 ^iV' ^k.'^t^V.■.t 1 lO: '^'- IlVnil ^ V.'i.J.'k j. ?rl Uil,'-;" 



cic Ds-\cvsi [a. 



ruljitri .'"?.oO.PriKiTC.sterPj« 



THE PLANT. 141 



the disintegrator itself, as it has a much 
harder pull on it ; and if the engine is simul- 
taneously employed on other work, it is also 
very desirable that this pulley should have a 
loose one of the same size alongside of it, to 
admit the machine being thrown out of gear 
without stopping the engine. Of course, in 
this case, the pulley on the engine-shaft must 
be made double the breadth otherwise re- 
quired for the purpose. 

" Thus, having the means of throwing it 
in and out of gear is especially desirable 
with the large 6 feet 3 inches machine, the 
great weight of which makes it awkward to 
start at full speed, which is readily avoided 
by slowly shifting the strap from the loose 
pulley to the fast one, a partial slip of the 
strap ensuing during the gradual transit, 
which diminishes the abruptness of the start- 
ing. 

" Besides, without the loose pulley, the en- 
gine itself, would be found difficult to start 
with the largest size machine in gear with it ; 
for the power of a single engine on its first 
half stroke, is nearly wholly expended in 
giving motion to its own fly-wheel ; and if it 
had simultaneously to start a heavy machine 
also, and that at a speed very much greater 
than its own, it would be exceedingly liable to 



142 PURE FERTILIZERS. 

be brought up when the crank lost its leverage, 
and came upon its dead centre, its fly-wheel 
not having attained sufficient momentum to 
carry it over. Nor is this all, for while the 
engine is awkward to start when unfreed 
from the disintegrator, it is under the same cir- 
cumstances equally difficult to stop it quickly, 
for the great speed and weight of the large 
sized one gives it sufficient momentum to 
powerfully re-act upon the engine when the 
steam is cut off, and drive it round many 
more times than its fly-wheel only would 
have done. 

" The straps should be very stout ones, and 
if double sewn so much the better. The one 
to drive the intermediate shaft should be 8 
or 9 inches broad, and the two that come 
from it to the disintegrator should be 7 
inches broad. All new straps will be found 
at first very troublesome, until by use they 
have ceased to stretch. 

" Stout belts of the same breadths will do 
as well as leather straps. The cross strap 
or belt should not be allowed to scrub against 
itself at the crossing, but should be kept 
separate by a small iron friction roller between 
it, 2^ inches diameter and 15 inches long, 
rotating on a vertical axle | in. diameter, sup- 
ported top and bottom. This would greatly 



THE PLANT. 143 



save the strap from friction and wear, and it 
is especially desirable when belts are used. 

" It is indispensable that the cage should 
be enclosed in some way by an external 
casing or chamber, in order to arrest and pre- 
vent the too wide dispersion of the material, 
as it flies out with great force from every 
portion of the periphery. The shape of it, 
however, is of no importance so long as it 
effects this, and also shelters the straps, bear- 
ings, and men from the material falling on 
them, and at the same time admits of the 
machine being conveniently fed, and the 
finished material removed. But care should 
be taken that it is not so restricted that the 
material may be liable to cake and jam be- 
tween it and the sides of the machine, thereby 
acting like a friction-break on it, and involv- 
ing great waste of power. For it must be 
borne in mind that resistance caused by any 
such unnecessary friction here, is multiplied 
against the engine as many times as the 
speed of the disintegrator exceeds that of the 
engine, and therefore becomes very serious. 
A simple hopper sloping into the machine 
would be found convenient to guide the ma- 
terial in. The casing should be made to sepa- 
rate, so as to enable the workman to con- 
veniently scrape from it, occasionally, any 



144 PURE FERTILIZERS. 

material that may have caked against it in- 
side, opposite the bars, between which and 
the casing there should be a clearance of 15 
inches at least, and if double or treble that, so 
much the better, when the material is pasty. 

" With the high speed this machine is 
driven at, and considering the large amount 
of work it does, it would be false economy to 
stint it of oil, especially while new and the 
bearings not worn smooth and free, and there- 
fore more liable to heat. When working 
continuously at full speed, from two to three 
pints of oil a day, if found necessary to keep 
it cool, should not be grudged, especially 
while new ; and it should be inspected occa- 
sionally to see that the brasses do not get in- 
juriously hot. 

"When the raw material has not far to be 
brought to it nor the finished material to be 
far removed, five men will be sufficient to do 
fifty tons a day with it : two bringing up the 
material to it, one shoveling in, and two re- 
moving ; but with more men, two shovelers, 
and adequate power, the machine is capable 
of doing double that quantity. When the 
materials are hard and of considerable speci- 
fic gravity, the user must be especially cau- 
tious not to throw into a disintegrator of 
moderate strength solid pieces of an inordi- 



THE PLANT. 145 



nate weight, or he may do more damage to it 
thereby in five minutes than five years' legi- 
timate work would eft"ect. The knife, with 
such hard materials, should be dispensed 
with." 

"When a soft and very adhesive material 
is used, a portion of it will adhere to each bar, 
but never on the side of the bar which strikes 
the material, but on the back side of the bar 
as regards the direction it is moving in. If, 
therefore, the engine is furnished with re- 
versing gear, and can be conveniently driven 
occasionally in an opposite direction, the 

Note. — There is a more modern mixer than Carr's, 
which, though not known in Great Britain, is spoken of 
very favourably by the many manufacturers throughout 
the United States, who use it there. The annexed draw- 
ing will give an idea of this machine as constructed by its 
inventors, Poole and Hunt, mechanical engineers, at Balti- 
more, Maryland. 




The containing vessel is an iron pan revolving hori- 
zontally around a support ; and in this pan a rubbing or 

L 



146 PURE FERTILIZERS. 

machine will soon clean itself. Or the same 
might be effected, but with more trouble, by 
unlacing the straps, and making the cross 
and open straps exchange pulleys. Or the 
cleaning may be effected without either of the 
above plans : viz., by throwing in, while at 
full speed, a hundredweight or two of any 
brittle material, such as bone-ash or copro- 
lite." 



mixing apparatus turns about its support. In combina- 
tion with these two parts there is a guiding device for 
causing the rotation of the pan and mixer to move the 
mixed material to the central opening in the pan, through 
which it drops into a conduit or other suitable arrange- 
ment for being carried away. 



CHAPTER VI, 



THE ARRANGEMENT OF THE FACTORY 
PLANT. 

The ground selected for a factory building 
should be in an open situation, and con- 
venient to the sources of the raw materials, 
as well as favourably located for cheap trans- 
portation of the finished products. The vici- 
nity of navigable water or a railway station, 
in a manufacturing centre, is, therefore, the 
most eligible position. 

The factory building must be spacious and 
freely ventilated, so as to prevent discomfort- 
ing and unwholesome effects on the work- 
men from the noxious vapours which are in- 
cident unavoidably to the operations con- 
ducted therein. As best fulfilling these re- 
quirements, the lower part of the building, to 
the height of 12 feet, may be of mason-work, 
pierced by numerous windows, the sashes of 

L 2 



148 PURE FERTILIZERS. 



which are hung upon pivots ; and the upper 
part wholly of wooden slat-work. The doors 
should slide on wheels and be very numerous 
in the front, so that a free draught may be 
obtained by opening them when the digestions 
are in progress. 

For the convenience and economy of super- 
posing the various implements, so that the 
contents of the upper may descend step by 
step and as required, through the series of 
vessels which are placed beneath, with as 
little delay and manual assistance as possible, 
the height of the main apartment should be 
35 to 40 feet, and that of the wings and shed 
15 feet. 

A syphon and several taps may be made 
thus to save the expense of many workmen, 
and also to render the apparatus as automatic 
as possible : an important point, considering 
the capricious character of manual labour. 

Plate 16 exhibits the general construction 
of a convenient factory, and the relative posi- 
tions of the several pieces of apparatus. 

It consists of two wings, c and G, a central 
apartment r, and a shed t at the rear. 

The left wing has four divisions, of which 



ARRANGEMENT OF FACTORY PLANT. 149 

the front one c, is the office, and the second 
B, an engine room. Back of the latter in a 
are the boilers, while to the rear of all that 
part of the shed a is to be used as the coal 
and ash room. 

The office is subdivided by a sash-work 
partition, into two parts, in order to furnish 
a laboratory c , for the analytical and ex- 
perimental work of the factory. This labor- 
atory must be wholly shut off from the 
engine-room, so as to protect the latter from 
the corrosive vapours of the former ; but this 
need not interfere with the introduction of 
the necessary steam-pipes. 

The ventilation may be made complete by 
means of the windows and register-openings 
in the flue, which serves for the sand bath. 

Gas is the fuel to be employed for the ana- 
lytical operations, and steam-pipes are the 
media for warming the room. 

The shed t runs the entire width of the 
building at the rear, and is only 12 or 15 
feet high. It is divided into several portions 
and fitted with suitable sliding-doors and 
windows. In the part b', the grinding and 
roasting operations are carried on, so as to 



I50 PURE FERTILIZERS. 

keep the main building free from dust. The 
position of the implements for this purpose 
is shown by n o p. It serves also for the 
storage of the crude minerals. The portion 
c is for general storage purpose ; while the 
part d serves for the fuel and work connected 
with the evaporating-pans and drying-kilns. 

The central apartment r is the general 
operating space. At the north-west corner 
the platform and its accessories m are placed, 
so as to be convenient to the grinding 
machines, from which the powdered mineral 
is shovelled through an opening e, at the 
base of the partition to the foot of the ele- 
vator. 

In front of the platform and elevator, about 
20 feet distant is the series of stone digesters 
or solution vats s; and in the ground beneath, 
but close to the left hand wall, so as to be 
out of the way of accident, are two monte- 
jus I I. 

The ordinary precipitation vats are placed 
at L L, which show two pairs, one of which 
L l', may serve as wash vats. 

The vats for special precipitation and fitted 
with air-chambers, are to be set at k. In 



A RRA NGEMENT OF FA CTOR Y PLANT. 1 5 1 

order to accommodate the large volume of 
wash-liquor, during its accumulation, for eva- 
poration, there is a tall reservoir q, for the 
reception and storage. 

At Y is the pug mill for converting the 
pulpy precipitate of phosphate of lime into 
superphosphate, and v vv v are the wells for 
the reception of the mixture of acid and pulp 
as it issues from the pug mill. In these 
wells it remains until chemical action is com- 
plete, and the mass has become hard. 

The drainers and a vacuo-vat for making: 
pure bi-phosphate of lime, or, in other words, 
for leeching superphosphate, have place at 
X and z. 

The right wing has several apartments. 
The first, in two parts, contains the evapor- 
ating-pan e, and the drying kilns d, both 
of these rooms being served with fuel and 
other attention from the shed-space d, in 
the rear. The division f in front accommo- 
dates the disintegrator, and the mixing opera- 
tion ; and the room g is that in which the 
finished products are weighed and packed for 
market. 

The upper part of this wing should be full 



152 PURE FERTILIZERS. 

of windows, moving on a pivot, to produce 
currents of air for facilitating the evaporating 
and drying operations, as may be found 
necessary. 

There are two chimney-stacks, one at h for 
the steam-boiler furnace, and the other h', 
connecting with the flues of the evaporating- 
pans and drying kilns. The main pipe, or 
feeder, for supplying the steam to the appara- 
tus should run along the wall so high up 
that the heating branches may drop from it. 
This arrangement will prevent them being in 
the way of a convenient manipulation. 

As a proper economy of the operation can 
only be secured by an uninterrupted progress, 
the work must continue day and night ; and, 
therefore, two sets of hands will be necessary, 
to replace each other at the proper intervals. 
A plant constructed and collocated, as has 
been described, will promote a comfortable 
and economical course of the factory-work. 



CHAPTER VII. 

THE RATIONALE OF THE PROCESSES FOR 
REFINING THE CRUDE PHOSPHATES OF 
LIME INTO PRECIPITATED AND DI- 
PHOSPHATES OF LIME. 

The methods about to be described for the 
purification of "rock guanos" and other mine- 
ral phosphates, are founded upon certain prin- 
ciples, which may be stated as follows : — 

1. The evolution of pure and concentrated 
products without any valuable ''waste' of the 
raw materials, and in a manner which secures 
alike to manufacturers and farmers the maxi- 
mum of honest profit and attainable benefits, 

2. The use of chemical agents, which are 
not only very abundant and cheap, but easily 
managed, and capable of being reclaimed in 
forms that will pay their original cost, apart 
from the profit on the pure phosphate pro- 
ducts. 

Artificial fertilizers arc manufactured al- 



154 PURE FERTILIZERS. 

most always in great commercial centres, and 
the customers for them live often in districts 
remote from convenient channels of distribu- 
tion. Hence the package and transportation 
expenses become most important items for 
consideration in connection with a manure. 
Previously to being sent forth into the mar- 
ket, it should be freed, therefore, from all 
inert matters ; for, to leave it burthened un- 
necessarily with any profligate constituents, 
is an imposition upon the confiding planter. 

Moreover, that manure is most economical 
and effectual which does its work through the 
first season of application ; for, though dura- 
bility is not incompatible with potency, the 
quality of permanence is superior only in the 
sense that none of the fertilizing virtue shall 
be lost by dissipation after the manure has 
been put into the soil. 

In other words, a soil should be manured 
rather for immediate fruitfulness than durable 
fertility : and thus half a ton of a pure and 
active fertilizer is worth double that quantity 
of a dilute or a sluggish one. The future 
had much better be left to the chances of a 
possible excess of the first than that the pre- 



REFINING PROCESSES. 155 

sent should be jeopardised by the imperfect 
qualities of the latter. In fine, a manure 
whose forces are being long drawn out 
through a succession of years, is an injudi- 
cious investment, which involves a large 
capital of money and patience. 

I realize these precepts, practically, in some 
instances, by attacking firstly the crude phos- 
phate of lime with that chemical equivalent 
proportion of hydrochloric acid which is just 
sufficient to decompose and dissolve out the 
whole of the carbonate and organate of lime 
constituents. 

The solution thus formed consists of chlo- 
ride of calcium, and is to be drawn off into a 
separate vessel ; for this liquor may be eva- 
porated to dryness and utilized profitably in 
the manufacture of artificial stone by Ran- 
some's process, or for solidifying the ammo- 
nia of the liquor of the coal-gas works and 
bone-black works, as taught in Chapter xi. 

These two lime constituents act most profli- 
gately in the usual process of treating crude 
phosphates ; for they are the first to seize the 
sulphuric acid, and only to waste it by swell- 
ing the volume and weight of the product 
with superfluous sulphate of lime. 



MORFIT on the Manufacture of'FertiUzrrs. 



PRECIPITATION VAT DETAILS 



Plate 11. 



I z 



Fio. I. 



'— ' ■ ' I '-n-^H ' I ' 



' L ' I ' _L. ' _l_i -----'^^^=^ 



I , I 



' I'^SE 



1 I 



SCALE OF FEET. 
6 7 8 9 10 11 1Z 13 14- IS 

— I 1 I I I I I I I rJ 




i^e: 



Fic. II. 



^ 



-e- 



-G- 

-e- 
-e- 



-Q- 



3^ 



I . I . I . I 



I.I.I, r 



I . I . I . ~r 



I . I -I 



I . I r 



I , I 



I'D^ I 



1 r 



I 1 



I I 



'I . I 



I I — r 



I I 



III 



Fic. Ill 



I 



^3 — CTn r—o — C7- 



Fic. IV. 



SCALE OF FE ET. 



i i . 1 . I I , I. 



Spsoaliy diDij^u-ditM U'MwiUaWui-kolit'ui-lilincrS, 



VllKOiiL bi\.)uto Ijayi-ijn uiJ' 



FiC. V. 



I I I ^ 



~[^2— Lv\Aw|~ 



riikiM'^ CV.DO.PaiwiioSJef I's 



156 PURE FERTILIZERS. 



In my processes, on the contrary, the much 
cheaper hydrochloric acid is made to do not 
only that which sulphuric acid would fail to 
accomplish, but in such a manner that it may 
be reclaimed in forms which countervail its 
original cost. 

The second step in the refining operation, 
then, is to add hydrochloric acid again, and 
in rather greater proportion than will suf- 
fice to dissolve out the phosphate of lime 
and other soluble constituents of the mine- 
ral. There is thus left only the insoluble 
and inert matters, which are to be thrown 
aside as valueless. 

The liquor being drawn off into a separate 
vessel is a hydrochloric solution of phosphate 
of lime and magnesia, with certain impuri- 
ties, and represents the whole essence and 
value of the crude mineral. 

Passing to the third step, which is to get 
back the phosphates in a solid form, I neu- 
tralize the hydrochloric acid of the liquor 
with a reagent, in such a manner, as to keep 
in solution the associate-impurities, while pre- 
cipitating the phosphate of lime ; and, at the 
same time, to reclaim, the precipitant in a 



REFINING PROCESSES. 157 

suitable form for indefinite repetitions of the 
operation or other useful purposes. 

The precipitate which is thus thrown down 
being a pure phosphate of lime in the state 
of pulp, has all the qualities for a rapid and 
entire conversion into pure " superphosphate" 
by mere passage through the pug mixer, with 
its bare chemical equivalent of sulphuric acid. 

There is, consequently, no v/aste whatever 
of acid, time, or labour, nor any crowding 
out of the soluble bi-phosphate element to 
make room for the intrusion of an excess of 
sulphate of lime or the presence of worthless 
matters. 

The product consists wholly of soluble bi- 
phosphate of lime in association with only that 
amount of hydrated sulphate of lime which is 
incident, unavoidably, to the chemical conver- 
sion of tri-phosphate into bi-phosphate of lime. 

This high degree of purity of the " super- 
phosphate" affords the facility of producing a 
soluble bi-phosphate of strength as great as 
100 per cent. For, by simply leeching the 
pure " superphosphate" with water, all the 
soluble bi-phosphate is removed from its sul- 
phate of lime associate, and may be obtained 



158 



PURE FERTILIZERS. 



as a crystalline mass by evaporating the 
liquor to dryness. 

The following diagram presents a summary 
of the progressive operations and their effects. 



Components of the mineral. 



Action & products of the processes. 



I. 



Carbonate of lime 



I Oi'cfanate of lime 



r Removed by the first dose 
or fractional of hydro- 
chloric acid ; and re- 
\ claimed subsequently as 
chloride of ammonium or 
chloride of potassium and 
hydrated sulphate of lime. 



■ Tri-phosphate of lime^ 
with all or most of the 
2. \ iron and aluminum < 
oxides and phos- 
phates - - - - - 



^ Sand and silica - - - 
Organic matter - - - 
Fluoride of calcium, 

with more less of 
Oxide of iron - - - 
Oxide of aluminium - 
Phosphate of iron and 
Phosphate of alumina - 



Dissolved out by the second 
dose or fractional of hy- 
drochloric acid and sepa- 
rated from the liquor in 
pure solid forms, indivi- 
dually ; by agents which 
are reclaimed subse- 
quently. 



l-\ 



Left as insoluble residue 
by the hydrochloric acid, 
and to be thrown away 
as valueless matters. 



REFINING PROCESSES. 159 

There are many cases, however, in which 
the mineral phosphate will not yield its car- 
bonate and organate of lime constitutents to 
hydrochloric acid, without parting, at the 
same time, with more or less of the phos- 
phate of lime element ; and, therefore, the 
first fractional treatment may be considered a 
matter of expediency determinable for each 
case, according to the judgment of the ope- 
rator. 

If the first fractional treatment or digestion 
with hydrochloric acid is omitted, or rather 
merged into the second, so that the two be- 
come one and continuous, then the resulting 
solution differs from that of the previous in- 
stance only in containing more chloride of 
calcium ; the additional quantity of the latter 
being formed from the carbonate and organ- 
ate of lime constituents of the raw mineral. 

This chloride of calcium increases the 
volume and density of the liquor, so that 
more time and fuel are required in the subse- 
quent manipulations; but it is not, otherwise, 
an obstructive presence or modifier of the 
reactions hereinbefore explained. 

To get back the phosphate of lime of the 



i6o PURE FERTILIZERS. 

entire liquor thus made, either ammonia, car- 
bonate of ammonia, or carbonate of lime will 
answer as the precipitant, and the mother- 
liquor will have the composition of that al- 
ready described. But, when di-phosphate of 
lime is required instead of tri- or Colombian 
phosphate, either alumina, phosphate of alu- 
mina, oxide of iron, phosphate of iron, or 
milk of lime, must be substituted, as the pre- 
cipitant, for economical reasons. In each case, 
the precipitant being the stronger base, seizes 
the hydrochloric acid which holds the phos- 
phate of lime in solution and causes the latter 
to precipitate as a white powder. The mother- 
liquor is then a hydrochloric solution of the 
precipitant which may have been employed, 
together with more or less of chloride of cal- 
cium and the iron and aluminum constituents 
of the mineral. 

As the use of a full equivalent proportion 
of the precipitant would produce tri-phos- 
phate, the quantity is reduced to one half of 
the chemical equivalent of the tri-phosphate 
of lime contained in the liquor when it may 
be desired to make the precipitation as di- 
phosphate of lime. 



REFINING PROCESSES. i6i 

The quantitative adjustment of the precipi- 
tant, so as to restrict the ratio to the require- 
ments for producing either a tri- or di-phos- 
phate, leaves all the iron and aluminium com- 
pounds in the mother-liquor and delivers the 
lime phosphate in a pure state. Thus, then, 
the latter not only acquires an enhanced value, 
but promotes for the mother-liquor a wider 
and more profitable range of usefulness. 
The latter being now a hydrochloric solution 
of aluminium and iron oxides and phos- 
phates, is, in fact, a counterpart of the acid 
solution of "Alta Vela Guano" or other 
mineral phosphate of alumina as specially 
made for the defecation of sewage. It has 
all the advantages of this liquor, with the ad- 
ditional one of much greater cheapness. 

So great is the precision with which these 
re-agents may be made to separate the phos- 
phate of lime from its usual persistent asso- 
ciates, that I intend to found, also, an analy- 
tical process in connection with them, and 
thus solve a problem which, until now, has 
been full of chemical difficulties. 



M 



CHAPTER VIII. 



THE MANUFACTURE OF PRECIPITATED 
PHOSPHATE OF LIME. 

This product is in the form of a loose white 
powder, and has a fertilizing capacity only 
less potential than that of the Colombian 
phosphate, described in the next chapter. 

Chemical authorities generally consider it 
to be wholly a tri-phosphate of lime ; but 
it usually contains also some di-phosphate. 
Practically, it is a mixture of all three of 
the phosphates of lime ; for, being very sen- 
sitive, it splits into these latter promptly, 
under the chemical influences of the soil. Its 
degree of chemical tenderness in this respect 
varies with the density and temperature of 
the acid solution from which it is precipi- 
tated, and accordingly as the precipitant may 
be used in the gaseous or liquid state. 

It may be made pure, provided the raw 



PHOSPHATE OF LIME. 163 

mineral is free from alumina and oxide of 
iron, and in any case it need not contain 
more than two or three per cent, of these 
matters, if proper care is observed in its pre- 
paration. 

Being free from foreign matters, that is, 
commercially pure, its superiority as a raw 
material for conversion into " superphos- 
phate" of very high degree, or even into a pure 
bi-phosphate, is very evident. The employ- 
ment of it for this purpose will not only re- 
duce the required amount of labour and acid 
to the lowTst possible ratio, but prevent all 
waste and unprofitable dilution of the pro- 
ducts. Moreover, the latter will be both dry 
and bright-coloured, in characteristic degree. 

Hitherto, all attempts to use ammonia as 
the precipitant have failed in practice on a 
large scale, because of the difficulty of adapt-, 
ing a suitable apparatus to the bulky volume 
of the raw materials and freeing the precipi- 
tate from that hygroscopic property which 
adheres to it through the presence of a slight 
proportion of chloride of calcium. However 
much the precipitate may be washed, this 
property cannot be removed by water alone. 

M 2 



1 64 PURE FERTILIZERS. 

B. de Siebenthal was the first to suggest the 
reclamation of the ammonia precipitant, but 
omitted to describe the means. Moreover, 
he proposed the use of it in a liquid form as 
precipitant, which is impracticable, for that 
would require an immense stretch of appara- 
tus and labour for an operation of even mo- 
derate extent. 

The removal of these fatal obstacles was 
not an easy task ; but they have yielded in 
my conflict with them, and I am now able, 
after a patient study of the subject, to present 
the following method of manufacture, which 
is at once simple, practical, and, in all re- 
spects, economical. Though this process is 
able to evolve pure products from mineral 
phosphate of even poor and complex nature, 
it is yet expedient, for the sake of convenient 
manipulation and uniform results, that the 
manufacture should be conducted as much as 
possible with minerals of uniformly fair com- 
position and character. The ''South Caro- 
lina Phosphate \ therefore, will be taken as 
the raw mineral, with which to exemplify the 
following instructions. 



PHOSPHATE OF LIME. 165 



The Purge or First Fractional Digestion 

The first step is to grind the raw mineral 
to fine powder, after which it should be well 
heated in a reverberatory furnace to dull red- 
ness for an hour. By this process of roast- 
ing, the iron constituents are reduced to the 
lowest degree of solubility in hydrochloric 
acid, and thus both the purity of the refined 
product and the economy of its manufacture 
are materially promoted. 

Moreover, part of the carbonic acid being 
driven off from the carbonate of lime element, 
there will be less inconvenience from effer- 
vescence in the subsequent digesting opera- 
tion. So, also, in like manner, any pyrites 
which may be present is converted into oxide 
of iron and the subsequent evolution of sul- 
phuretted hydrogen during the digesting 
with acid will be counteracted. 

At the same time, it must be mentioned 
that the presence of organic matter will cause 
the roasted mass to retain a certain amount 
of soluble carbon product, which occasionally 
renders more difficult and slow the subse- 



1 66 PURE FERTILIZERS. 

quent digesting operation and clear settlings 
of the liquors. 

Care must be observed in this roasting 
operation not to fuse the powdered mineral, 
more particularly when there is much sand 
or silica present ; otherwise, this latter, in 
connection with some of the other foreign 
constituents, might re-act upon the phos- 
phate of lime element and diminish its solu- 
bility in acids. 

The powdered raw mineral phosphate, 
having been roasted, is to be brought to the 
foot of the elevator plates 5 and 6, and 
taken up by the cups ;/ ;/, so as to pass into 
the mixer b gradually, with a sufficient 
quantity of hydrochloric acid of specific 
gravity I'ly to decompose and dissolve out 
its carbonate and organate of lime consti- 
tuents. 

Assuming that "South Carolina phosphate" 
is the mineral under treatment, and that it 
has the composition noted in the table at p. 
30, then its content of carbonate and organate 
of lime being 14*32 per cent, every hundred 
pounds of the mineral will require 30*93 
pounds of hydrochloric acid (sp gravity riy) 



PHOSPHATE OF LIME, 167 

and 3*o additional for contingencies, or say 
a total of 35 pounds for this preliminary step 
of the refining operation. 

The acid is to flow from the reservoir v 
(Plates 5 and 6) in a gradual stream, so that 
it will come in contact with the powdered 
mineral at the moment the latter enters the 
mixer (Plate 7) from the cups 11 n of the 
elevator ; and it may or may not, according 
to the judgment of the operator, be previously 
diluted with one-fourth of its volume of water. 
My own opinion is in favour of the dilution ; 
for it may happen, otherwise, that the mass 
will set into a stiff paste with only the volume 
of liquor represented by the strong acid. This 
consistence retards digestion in much greater 
degree than would the addition of water as 
suggested. 

The moist mass, as it falls from the mixer, 
is to be led through a wooden gutter into the 
stone digestion-vat described at p. 117, and 
shown by Plate 8. Here it is heated by the 
steam currents until effervescence has ceased. 
At this stage all of the carbonate and organ- 
ate of lime has been removed by solution in 
the acid, and together with more or less of 



i68 PURE FERTILIZERS. 



the iron and aluminum elements of the crude 
mineral. The liquor thus formed is to be 
drawn off, by means of the syphon, fig. 3, 
into the monte-jus (Plate 10, page 123). To 
the residue in the vat, fresh water is to be 
added, and the whole heated and stirred by 
the steam current as before, and then allowed 
to settle. The supernatant wash water is 
now to be drawn off into the monte-jus and 
mixed with the previous liquor for treatment, 
as explained in a subsequent chapter. It is 
to be known as i\\t purge liqttor. 

This fractional treatment of the mineral, 
with a restricted portion of acid as the first 
step of the refining operation, leaves it free 
• from those of its constituents, which would 
embarrass, otherwise, the subsequent mani- 
pulation by producing an excessive volume 
of liquor. Therefore, the contents of the 
vat now consist only of the phosphate of 
lime, constituent with sand, silica, organic 
matter, a portion of the aluminium and iron 
compounds, and fluoride of calcium, if any 
were present. 



PHOSPHATE OF LIME. 169 

The Solution oy Second Fyactional 
Digestion. 

The second step is to relieve the phosphate 
from its objectionable associates, and this 
must be accomplished by a new treatment of 
the washed residue with hydrochloric acid. 
As the original mineral contains 52'2i per 
cent, of tri-phosphate of lime, every 100 
pounds will require 137, or say 140, pounds 
of hydrochloric acid, of specific gravity I'ly, 
for this progressive stage of the refining pro- 
cess. It is to be poured directly upon the 
contents of the vat, after which the cover is 
lowered, and the whole heated and stirred by 
means of the steam currents until all the tri- 
phosphate of lime has been taken up in solu- 
tion. It is necessary to keep the vat covered 
during the digestion, otherwise there will be 
a great loss of acid by evaporation, and con- 
sequently an imperfect result. 

The whole is then allowed to settle, after 
which the fluid portion is to be drawn off 
into a monte-jus. The residue in the vat is 
then treated with fresh water, boiled, and 
allowed to settle as before. The wash water 



I/O PURE FERTILIZERS. 

having been drawn off into the monte-jus, 
there to mingle with the previous strong 
liquor, is to be washed a second time. The 
residue, having been thus cleaned of all its 
valuable matter, is now to be thrown out as 
waste, in order to make room for a charge of 
fresh mineral. 

The strong liquor and its two wash- 
waters in the monte-jus form a hydrochlo- 
ric solution of phosphate of lime, com- 
prising some little of iron and aluminium 
compounds, and represent the essence of 
the " South Carolina Phosphate" disembar- 
rassed of profligate and worthless associates. 
It now remains to get it into a solid form 
by means which are as convenient and self- 
compensating as possible. This has been 
rendered comparatively easy by the clean- 
ing away of the lime carbonate and organate 
in the first instance, and the contrivance of 
the following apparatus for the use of am- 
monia, in a gaseous state and for an indefinite 
number of repetitions, as the precipitating 
agent. The volume of this liquor, including 
wash-waters, is about 350 to 400 gallons from 
each ton of raw mineral under operation. 



PHOSPHATE OF LIME. 171 

The Precipitation and the Vacinun — 
Filter Vats. 

Therefore, to proceed with the next or third 
step, the hydrochloric solution of tri-phosphate 
of lime must be raised from the monte-jus 
into the tall cylindrical vats shown by b b 
(Plates 17, 18, and 19), and through the 
openings ^"^'' (Plate 17). 

As the volume of the liquor expands largely 
in absorbing ammonia, a vat must not be 
filled to more than two-thirds of its height. 

Four vats, b b b b, and one generator, a, 
constitute a battery. This arrangement is 
with a view to economy of apparatus and 
space. In any case, at least a single pair of 
vats will be necessary for an uninterrupted 
progress of operations. 

The vats, as well as the generator, are in 
two cylindrical pieces of the best cast iron, 
bolted together at joints as shown, and made 
steam-tight by means of a type-metal or 
caoutchouc ring inserted. The height of each 
piece is nine feet, which makes a total depth 
of eighteen feet for the vats and generator 
severally. The lower piece is to have a thick- 



\^2 PURE FERTILIZERS. 

ness of one inch and a quarter for strength, 
but the upper may be an eighth of an inch 
thinner. Both the bottoms and tops are 
fitted on with steam-tight joints. 

The four vats are identical in construction, 
and receive their necessary charge of gaseous 
ammonia from the generator a. For this 
purpose there are connecting pipes o o o o, 
made of cast-iron, leading from the directing- 
valve e, and each terminating in two cocks 
p p, at the distances shown from the bottom 
of the vats. By this arrangement with the 
interior, the gaseous ammonia is thus made 
to pass from the generator through nearly the 
whole volume of liquor in the precipitation 
vat, by merely opening the lower and closing 
the upper one of the cocks//. When, after 
a time the bottom stratum of the liquor may 
have become thick with precipitate, the upper- 
most of the cocks is to be opened and the 
lower one closed, to prevent the further entry 
of the ammonia to that part which is already 
saturated. 

For the free exit of any gas that may 
escape absorption or be in excess, there is a 
cast-iron pipe s rising from the top of each 



PHOSPHATE OF LIME. 173 



vat and dipping into a small cast-iron extra 
cistern / adjoining. This extra cistern is to 
be two-thirds filled with the original hydro- 
chloric solution of phosphate, and one of them 
will suffice for each pair of precipitating vats. 

The amount of gas escaping in this way 
will be so small, comparatively, that one 
charge of liquor will serve for many opera- 
tions, so that it will not need to be often re- 
placed by a fresh portion. As the precipita- 
tion which takes place in this cistern corre- 
sponds with the precipitation going on in the 
vats, the contents of the former are to follow 
the course of that of the latter, as soon as 
they have become thoroughly neutralized by 
the ammonia gas. 

The three cocks n ii n in each vat for test- 
ing the height of the contents within are 
fitted to a descending tube for carrying off 
the small try portions of liquor, and thus 
promote the convenience and comfort of the 
workman. 

There are also a hydrant-pipe g, and a 
steam-pipe /, connexion. The steam-pipe, 
descending into the vat from the latter, is to 
be perforated here and there throughout its 



174 PURE FERTILIZERS. 

length, so that the contents of the vat may 
be stirred and intermixed thoroughly by an 
occasional " blow-up T 

In order that the vats may serve equally 
for the precipitation of the phosphate liquor 
and the filtration of the precipitate, their 
bottoms have a special construction ; that is, 
the under portion of each has an air-tight 
communication with a vacuum chamber v v, 
by means of the short pipe and cock ;/ ;/ n n. 
One of these chambers will suffice for a pair 
of vats. It is of the best cast iron, seven 
feet high, with an internal diameter of three 
feet, and fixed below the level of the precipi- 
tation-vats. 

Air is exhausted from the vacuum chambers 
by means of an air-pump x, communicating 
with each through the pipes ;/ ;/ (Plate 19) ; 
or steam may be used to form the vacuum. 
In this latter case, there must be a pipe /' con- 
necting with the steam-pipe from boiler, and 
a pipe g attached to the hydrant which sup- 
plies the other vats with water. This arrange- 
ment is shown by Plate 17 and will be ex- 
plained directly. 

The details of a precipitation-vat are shown 



PHOSPHATE OF LIME. 175 

by Plate 18, fig. i, being a sectional elevation 
through the centre of the lower portion ; and 
fig. 2, a transverse sectional plan. In both 
of these figures, the letters of reference corre- 
spond for the same parts. 

a a are the sides of the vat, and b b the iron 
frame, bolted to the vat, in which slides the 
wedge-shaped door c. Bolted or cast upon 
a portion of this door-frame is a shoot d. The 
door c is raised or lowered by means of the 
screw e and the nut f. The gearing to this 
door consists of a bracket g bolted to the side 
of the vat, and, carrying the end of the screw, 
a pair of mitre wheels //, and a winch handle 
i, for raising, lowering, and screwing the door 
tightly into the wedge-shaped frame. 

The bottom of the vat k is strengthened by 
the ribs /////, and made to rise a certain 
distance into the interior of the vat, so as to 
make the level of the filter-plates ;;/ corre- 
spond with that of the bottom of the door, 
and also to give an inclination from the edge 
towards the centre, except at 11, immediately 
opposite the door. At this point it is left 
level, to facilitate the emptying of the vat after 
each precipitation. 



MOB FIT oil fhe Mccnu/actare ofFcj-tiUzcrs. 



Plate l: 



DRYING Kiln 



Fig. 




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Sectional Elevation. 



Fic. II 






t/////././/////^^^^^^^^^ I 




m. 



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I 



Sectional Plan. 



Scale of Feet 



i>jiecia\iy iJesignedtbrDrMorfilsV/oritoii t'«uLiz 



iBnxiks DavxSon Lith 



rr'jVa'rfr •^'^.■SO p?.-' 



1/6 PURE FERTILIZERS. 

Below the filter-plates the bottom is funnel- 
shaped, and terminates in a bend and flange, 
to which is joined the pipe that establishes 
communication with the vacuum-chamber. 
These filter-plates, m, are twelve in number, 
each one being a sector, so that it may be 
introduced conveniently through the door. 
Six of these are placed in position on the 
ribs 0, and covered with a coarse twilled 
woollen blanket. Over this are then set the 
remaining six plates, this arrangement being 
intended to prevent the clogging and over- 
weighting of the blanket. 

The dimensions of the several parts will 
be indicated by the scale attached to the 
drawings. 

The hydrochloric solution of phosphate of 
lime having been mounted into the precipita- 
tion-vats, by means of a monte-jus of ordinary 
construction, is ready to be treated with its 
required dose of gaseous ammonia. 

The Ammonia Generator. 

As before noted, the ammonia is evolved 
in, and sent forth from, the generator a (Plate 
17); but, before proceeding to explain that 



PHOSPHATE OF LIME. 177 



manipulation, I will complete my description 
of this part of the battery. In material, pro- 
portions, and chief points of construction, it 
is like the precipitation-vats. 

In the centre of the top is a manhole and 
lid of eighteen inches diameter, bolted on and 
joined in the usual manner, and made steam- 
tight by means of an inserted ring of type- 
metal or indiarubber. 

At the lower part, and on the side level 
with the bottom, is a sliding door m, like 
that which has been described for the pre- 
cipitation-vat on page 175, and by figs, i and 
2, Plate 18. 

On the top of this generator is an arrange- 
ment, a, for feeding it with the ammoniacal 
wash or mother liquor, during the generation 
of the ammonia. An elevator, b (Plate 17), 
of the usual construction, brings up the am- 
moniacal matter from a suitable reservoir in 
the ground beneath, and drops it into the 
hopper of the generator. On the top of the 
generator is a relief-valve, c, opening inwards 
to prevent regurgitation of the liquor from 
the precipitation-vats, in case a partial vacuum 
should occur in the vat from any cause. A 

N 



178 PVRE FERTILIZERS. 

safety-valve, d, is to restrict the pressure 
within a certain point ; and the gas generated 
within is carried off and conducted into either 
of the four precipitation-vats by means of a 
valve, Cy of special construction. 

Water is injected from the main supply, f, 
through the small pipes, g (Plate 17), as may 
be required. 

The current of steam, for heating the con- 
tents, enters from the main feeder, h, through 
the smaller branch-pipe, /. This latter dips 
to the level of the bottom and there diverges 
in two branches, k and /, each of which com- 
municates with a semicircular pipe laid round 
the interior and on the bottom of the vat. 
These two internal pipes form a ring, with 
their terminal ends abutting at opposite sides 
of the door ;//. They are perforated through- 
out their length or circumference with small 
holes for the issue of the steam at high 
pressure, for heating and stirring the contents 
of the generator. 

At the rear of the generator, or on the 
opposite side to the one seen in the drawing, 
are three try-cocks at different heights, and 
similar to those (;/ 1111) of the precipitation- 



PHOSPHATE OF LIME. 179 

vats. These are gauges for determining the 
height of the liquor within or drawing it off. 

The generator, like the precipitation-vats, 
is erected upon a mason-work foundation 
rising four feet above the level of the ground ; 
but, unlike them, is surrounded to within six 
inches of the top flange, by a brick wall, with 
an intervening space between it and the cast- 
ing. This space is to be filled with ashes, 
powdered coke, felt, or other non-conducting 
material, to confine and economize the heat. 

A wooden platform, constructed at a level 
of about two feet below the top flange, so as 
to surround the battery, and with a suitable 
stairway, is to afford easy access to the covers, 
joints, etc., on the tops of the vats. 

Plate 18 gives the details of the feeder to 
this generator ; fig. 3 being a transverse sec- 
tion at right angles to its axis; fig. 4, a longi- 
tudinal section through the centre parallel to 
the axis; fig. 5, a complete elevation from the 
front ; and fig. 6, a complete elevation from 
the side. The letters of reference correspond 
for the same parts throughout all these 
figures, a is the hopper into which the 
semi-fluid ammoniacal matter is elevated by 

N 2 



i8o PURE FERTILIZERS. 

the endless lift, and it is of large size, in 
order that it may be kept always partially 
full. Running up the outside of the hopper 
is a tube b, terminating at one end in a long, 
narrow orifice, and at the other in a pipe 
which dips into a small condensing cistern, 
as shown by c and d' in Plate 17. 

The gas which rises from the generator 
and fills the apparatus at each revolution 
escapes by its own elasticity, in part, through 
this aperture when it is first opened ; and the 
remainder is forced up by the descending 
mush liquor. As the revolution continues, 
the aperture at the base of the hopper be- 
comes uncovered, and the contained mush 
liquor falls through into the generator. 

^ is a cylindrical chamber with closed ends, 
and the greater portion of its sides cut away, 
leaving only the two opposite parts g g, and 
the diaphragm h, which divides it. This 
chamber is turned, truly, to a slightly conical 
form, so as to insure the maintenance of a 
continuous good fit as wear and tear take 
place. 

The projecting collar /, or exterior flange 
at the large end, prevents the forcing of it in 



PHOSPHATE OF LIME. i8i 

too tightly, and a centre screw k, regulates 
the proper degree of pressure, and keeps the 
inner cylinder in position as wear and tear 
progress. 

/ is the outer casing, open at each end, and 
bored to fit the chamber e. It is cast in one 
piece with the hopper, and terminates at the 
bottom in an aperture corresponding to the 
one at the base of the hopper and exactly 
opposite to it. This is extended in the form 
of a short pipe ;//, with flanges by which it is 
bolted to the top of the generator a. 

71 is a worm-wheel fixed on a spindle firmly 
keyed into a socket o, cast upon the centre of 
the end, and concentric with the cylindrical 
chamber e. Rotary motion is communicated 
to this wheel by means of the spindle which 
carries the worm r, and is driven by a strap 
from the main shafting running on the pulley 
s s. A bracket t, to carry this gearing is 
bolted upon lugs cast on the side of the outer 
casing /. 

These are drawn to the same scale as the 
two previous figures. The ammonia mate- 
rial or materials are to be carried to the hop- 
per by the lift, and the feeding must be so 



1 82 PURE FERTILIZERS. 

arranged as to keep the hopper nearly full. 
Motion is then given to the pulleys by means 
of a strap from the main shafting, and is 
transmitted by means of the worm and wheel 
to the inner cylinder. As this revolves from 
left to right, the portion g passing from the 
base of the hopper allows the contents to fill 
the space e, and as the revolution continues, 
the contents of the space e are poured into 
the generating vat through the pipe ;;/, and 
at the same time the contained gas takes 
their place. The further continuation of the 
revolution then brings the contents of the 
opposite space into the vat, and the gas that 
has replaced the contents of the first space e, 
finds an escape through the pipe b, and is 
condensed by dilute sulphuric acid contained 
in a suitable vessel or receiver, as shown by 
d\ Plate 17. Coincidently, the material in 
the hopper again fills the space e, and forces 
all the gases up the pipe b. Thus, as long as 
the revolution is uninterrupted, the material 
is fed into the generating vat without any of 
the contained gases being lost ; for, as the 
contents fall into the generator, the corre- 
sponding opening through which the mush 



PHOSPHATE OF LIME. 183 

liquor enters the feeder is closed by the re- 
volving cylinder. 

Fig. 7, Plate 18, is a transverse vertical 
section ; and fig. 9, a transverse horizontal 
section of the four-way valve-cock by which 
the generated ammonia gas is distributed to, 
or shut off from, one or more of the four 
precipitation vats, as may be desired. A 
tell-tale window, of thick glass x, Plate 17, 
will indicate when any lime may be frothing 
over with the liquor ; and, in such case, the 
heating and agitation of the contents of the 
generator must be moderated. 

a a a a are the four branches, terminating 
each in a rectangular orifice b, of the same 
area as that of the circular one c, at the 
opposite extremity; ^is a hollow, conical plug, 
open at bottom, with one side aperture of 
same size as <^; <? is a handle by which it is 
turned, and the aperture /" made to coincide 
with that of either of four branches ; and g is 
a flange by which the whole arrangement is 
bolted to the top of a pipe, which is itself 
fixed to the top of the generator. 

The relief-valve, to prevent regurgitation 
of the contents of the precipitation vats into 



1 84 PURE FERTILIZERS. 

the generator, is shown in transvertical sec- 
tion by fig. 8, and in plan by fig. lo, Plate 
1 8. 

a is the outer casing; b, the valve, sup- 
ported by the spring c, by means of a collar 
and spindle d. This spring is only just 
powerful enough to bear the weight of the 
valve. 

The apparatus having been constructed 
and arranged, as described, and the hydro- 
chloric solution of the phosphate of lime 
mounted into the precipitation vat; the work- 
man then proceeds to charge the generator. 

This is done, in the first instance, with a 
very dense solution of chloride of ammonium 
as the material for eliminating the gaseous 
ammonia. For every pound of hydrochloric 
acid, of specific gravity riy, that may have 
been consumed in making the contents of the 
precipitatioit vat, there must be taken 0*5 1 to 
o*55 pound of chloride of ammonium. 

The ammonia liquor is mounted into the 
generator from the reservoir in the floor be- 
neath. When all of the requisite charge has 
entered the vat that is sufficient to generate 
that amount of gas which is necessary to pre- 



PHOSPHATE OF LIME. 185 

cipitate at least the contents of one vat, then 
it is to be followed by the proper equivalent 
of lime for its decomposition. This lime 
must be of the very best quality, and 
thoroughly slaked into a very thick fluid 
mush, as directed at p. 63. It is delivered 
into the generator by the elevator, but the 
cups of this machine must be always cleansed 
previous to changing their use from ammo- 
nia salt to lime mush, and vice versd. More- 
over, the addition of the lime mush to the 
contents of the generator must be very 
gradual, so that there may be sufficient time 
for a previous dose to complete its share of 
decomposing action upon the ammonia salt 
before being supplemented by a succeeding 
one. By this management, the contents of 
the generator will be kept in a fluid state re- 
quiring only a moderate heat, and having the 
capacity of being drawn out easily at the end 
of the operation. Moreover, it promotes an 
uninterrupted progress of decomposition, and 
obviates the inconvenience that would other- 
wise occur from a too large volume of liquor 
at any one time. 

The hopper-arrangement is expressly for 



1 86 PURE FERTILIZERS. 

accomplishing this gradual feeding of the 
ammonia salt with lime mush. 

All of the lime and ammonia salt may be 
even put together in the generator at once, 
instead of being fed one to the other by de- 
grees ; and, in that case, the feeding append- 
age a on the top of the generator becomes 
unnecessary, and may be omitted in the con- 
struction of the latter. 

So, also, the ammonia liquor may be put 
in first, and have the lime fed to it gradatini. 

A current of steam must be running into 
the generator from the instant that the lime 
begins to enter, or even sooner, so that the 
liquor may be warm to receive it ; and this 
steam-heating is to continue until all the 
lime has been consumed, or rather until the 
ammonia salt has been exhausted, as will be 
known when there is no longer any smell of 
ammonia given off by the gaseous distillate, 
as tested from the try-cock. 

Every pound of chloride of ammonium will 
require 0*53 pound of oxide of calcium for 
its decomposition, and this is equivalent to 
o"6o pound of the best quality of ''quick'' 
lime. 



PHOSPHATE OF LIME. 187 



In the use of chloride of ammonium there 
is formed gaseous ammonia, which is driven 
over, with a little moisture, into the precipi- 
tation vat, and aqueous solution of chloride 
of calcium, which remains as liquor in the 
generator, and is to be drawn out and econo- 
mised, as explained in Chapter xi. The 
generator is then ready to receive a fresh 
charge of material for immediate action on 
the contents of a succeeding vat. 

The current of steam which is let in to heat 
the mixture of ammonia salt and lime must 
be regulated so as to keep the temperature 
down to that point which will suffice to pro- 
duce the required chemical interaction; other- 
wise, some of the water might distil over 
with the evolved ammonia and dilute the 
liquor in the precipitation vats unnecessarily. 

The gas may be passed into one, two, 
three, or even four, of the precipitation vats 
at the same time ; and, for this purpose, all 
of the four ways of the exit- or deli very- valve 
must be opened. But the better plan is to 
have only two vats in connection simultane- 
ously, for thus one will be sooner finished ; 
and, at the same time, that which adjoins it 



PURE FERTILIZERS. 



will have absorbed all the gas which may 
escape condensation in the first. 

The liquor in a vat is known to be com- 
pletely precipitated when the clear filtrate 
from a small portion drawn through the try- 
cock remains unclouded upon being tested 
with aqua ammoniae ; and, at this moment, 
the current of ammonia gas is to be shut off. 

All of the precipitation vats should be 
kept charged with solution, so that, as soon 
as one is precipitated, the current of ammonia 
gas may be turned into another immediately. 

It may happen when the ebullition within 
is too strong, that some of the lime will be 
driven over, and to give warning of such an 
occurrence there is a tell-tale x, or small 
piece of thick sheet-glass set into the pipe. 
In such case, the heating and agitating of 
the contents of the generator must be mode- 
rated until subsidence of this frothing has 
taken place. 

If any slight excess of ammonia gas may 
have been absorbed, it must be economised 
by adding cautiously to the contents of pre- 
cipitation vats so much of fresh acid solution 
or of liquor from the extra cistern / as will 



PHOSPHATE OF LIME. 189 

just restore the point of neutralization, and 
this is to be determined by the use of litmus 
paper. 

The contents, having been brought to this 
exactly neutral point, are allowed to stand 
until the precipitate settles, when the super- 
natant clear liquor is to be drawn off through 
the cocks into a monte-jus. As all the car- 
bonate of lime was cleared away from the 
raw mineral in the first or preliminary stage 
of treatment, this mother-liquor is nearly a 
pure aqueous solution of chloride of ammo- 
nium, and needs evaporation to small volume, 
in order to be ready for use again as the 
ammoniacal wash. The amount of chlo- 
ride of calcium which it contains is only 
moderate. 

Notwithstanding the use of the blanket- 
cloth and the closing of the intercepting 
valve-cock w (Plate 19), some of the acid so- 
lution will pass through into the filter chamber 
a before its phosphate freight has been preci- 
pitated. This accumulated liquor must be 
drawn off, therefore, through the cock y (Plate 
19) immediately after the settling of the con- 
tents of the precipitation vat, and used for 



190 PURE FERTILIZERS. 

adjusting the neutralization point of liquor 
or mixed with fresh liquor. 

When the supernatant liquor has been 
drawn off from the deposit of phosphate in 
the vat, the latter is to be thinned with fresh 
water, heated and stirred by a ''blow tip\ and 
left to repose, in order that the mixture may 
clear and allow this wash water to be drawn 
off as before, and mixed with the previous 
strong ammoniacal wash in the monte-jus. 

One more washing with fresh water is 
necessary to cleanse the precipitate of any 
ammonium salt which it may have retained, 
and this must be done by percolation. 

It is to facilitate this operation and save 
labour that the precipitation vat is constructed 
as a vacuum-filter with a monte-jus annexed, 
as shown in detail by Plate 19. 

The precipitation vat b, to which this filter- 
arrangement is attached, has been described 
above, with reference to Plates 17 and 18, 
so that it is now only necessary to explain its 
accessories. 

The cast-iron filter-chamber a (Plate 19), 
receives the clear liquor passing through the 
blanket-filter-cloth from the precipitate, and 



PHOSPHATE OF LIME. 191 

delivers it through a connecting-pipe b, into 
a monte-jus v, which is constructed as a 
vacuum vessel. In the conduit b there is an 
intercepting valve-cock w, to be used accord- 
ing to requirement. 

The float d in the monte-jus is to indicate 
the height of the contents of the latter. This 
float is fixed to the end of a rod which passes 
through a stuffing-box / on the top, and has 
a chain end ff running over the pulleys h h, 
and terminating in a balance weight g. The 
counterpoise, thus established, will cause the 
float to rise or fall with the level of the liquor 
in the vessel. 

The pressure above or below that of the 
atmosphere is shown by a pressure and va- 
cuum guage /. 

The pipe / is the channel through which 
the contents of the monte-jus are mounted 
and conveyed into a storage-reservoir in 
some other part of the factory. During the 
operation of filtering, this channel is closed 
by means of the stop-cock in. 

A pipe n, connecting with the steam air- 
pump X, supplies the condensed air for work- 
ing the monte-jus ; and a second pipe ;/', 



192 PURE FERTILIZERS. 

serves for exhausting the monte-jus when the 
latter is to be used for filtrations. 

To each of these pipes is fitted a double 
valve 0, which, according to the portion that 
may be open, puts the air-pump in communi- 
cation with the monte-jus or the external 
air. Thus, to exhaust the monte-jus of air, 
the valve at o on the pipe 11 must be opened, 
as shown by the small separate figure x, 
Plate 19, while the valve immediately behind 
it on the pipe ;/' must be screwed down to 
the contrary position so as to intercept 
communication through the pipe n and put 
the air-pipe in communication with the atmo- 
sphere. 

The air-pump x is worked by steam power, 
and consists of an air-cylinder q, and a steam- 
cylinder X, with a valve-box /, containing 
one inlet and outlet valve for each end of the 
cylinder q, that is four valves in all. The 
plan of the cover of this valve is shown by 
the small and separate fig. c immediately be- 
low the air-pump in Plate 19. 

The steam-pipe of the cylinder r is shown 
at s and the exhaust at /. A short link it 
communicates rotary motion to a crank-shaft, 



PHOSPHATE OF LIME. 193 

from which the steam-valves are driven by 
the fly-wheel v. 

If it is desired to do the work by means of 
steam alone, then the air-pump x may be 
omitted by making the pipe ;/ communicate 
with the engine-boilers and replacing the air- 
pipe n by a small hydrant pipe. This is to 
furnish the cold water to condense the steam 
when a vacuum is to be formed on the 
monte-jus, as shown in Plate 17, where the 
pipe /' supplies the necessary steam, and the 
pipe g conveys the water, as previously 
noted. 

The mode of working the apparatus with 
air is as follows. The contents of the filtra- 
tion vat B being ready for leeching or wash- 
ing or draining, the valve w on the pipe /' is 
to be opened, and the cock ;;/ on the pipe / is 
to be closed. At the same time, the double 
valve on the pipe 11 must be screwed down 
tightly, so as to shut off passage through it, 
and put one portion of the valve case p into 
communication with the external air. The 
similar valve on pipe n is then opened to 
give free passage through the pipe between 
the other half of the valve case and the 



194 PURE FERTILIZERS. 

monte-jus vessel v. Steam is now admitted 
to the cylinder r of the air-pump, and reci- 
procating motion transmitted to the piston of 
the air-cylinder q. The air being thus alter- 
nately exhausted from the vessel v, and 
forced out through the open valve on the 
pipe //', there is a partial vacuum formed in 
the vessel v, which allows the whole pressure 
of the atmosphere to exert its force upon the 
surface of the contents of vat b, and drive the 
liquid portion through the blanket-filter and 
sieve bottom along the pipe /, into the reser- 
voir or monte-jus vessel v. 

The height to which it may rise in the 
latter is indicated by a tell-tale arrangement, 
consisting of the float d and balance weight 
g. The gauge k also will show the extent of 
the vacuum. 

When the vessel v is full, care being ob- 
served to prevent the mounting of the liquor 
through the pipe into the air engine, the 
valve w is closed. At the same time, the 
cock ;//, as also the valve on the pipe ;/, are 
opened, while the valve on the pipe 71 is 
closed. Thus the action of the engine be- 
comes reversed, and, compressed air being 



A 



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rrnTTiTry 



ill 

I! Mi 



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i]li_[lllill 



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PHOSPHATE OF LIME. 195 

forced into the vessel v, and acting on the 
surface of the contained liquor, forces it 
downwards more or less rapidly, and thence 
outwards and upwards through the pipe / to 
the required height or to the reservoir which 
is to receive it. 

All of these wash-liquors are to be mixed 
with the ammoniacal wash aforementioned, as 
they form part of it. 

The precipitate is quite drained in this 
way, and may receive a further washing, if 
necessary, in like manner, after covering it 
with fresh water from the hydrant. 

This done, the precipitate is ready to be 
drawn out through the opening and shoot 
<;«^ (Plate 18), either into the kiln (Plate 12) 
to be dried for market as precipitated phos- 
phate of lime, or into the pug mixer (Plate 
21) for conversion into superphosphate. 

If the precipitate is to be sold as such, it 

must be hot-washed just before going upon 

the diying-kiln, with about one per cent, of 

sulphate of ammonia in aqueous solution, to 

destroy any tendency to dampness which it 

might retain, otherwise, through the presence 

of traces of chloride of calcium. 

o 2 



MORFIT on llw Mrnuj/fuhur ol'h'crUJJ/yj'rs. 



iM.uo n 






1 














1 
1 




1 










1 


A' 








A' 




//* 




./ 


./ 




A' 





Fig. 2 



S,;il, 



EvAPOR ATI Nc Pan s 



■ila — r-Tfi 



•\ -■■ uliv 



i u tyVx^atM't^*^ 



196 PURE FERTILIZERS. 



If the vacuo-filtering and washing are to be 
promoted by steam-condensation instead of 
the air-pump, then the manipulation must be 
as follows : As directed in the previous in- 
stance, the valve w on pipe b must be opened, 
and the cock m on pipe / is to be closed. 
Steam is then admitted from the boiler 
through a pipe, as shown at /', in Plate 17, 
until it fills completely the vessel v, when it 
is turned off, and immediately followed by 
the injection of a spray of water through the 
pipe g (Plate 17). This spray must be suffi- 
cient to condense the steam, and thus make 
a vacuum which acts upon the surface of the 
contents of the generator in the same manner 
as when the air-pump is employed. The 
amount of the vacuum is registered by the 
gauge k, and this manipulation may be re- 
peated several times during the filtering of 
the vacuo-vat v, so as to maintain a good 
vacuum throughout the operation. 

When the vat v is full, the stop-valve w 
must be closed, and the cock in on the pipe / 
is to be opened. The steam being then 
turned on, acts by its pressure on the surface 
of the liquor, and forces it downwards and 



PHOSPHATE OF LIME. 197 

upwards through the pipe / into the reservoir, 
as required. 



The Ammoiiiacal Wash or Mother-Liquor. 

The mother-liquor, from which the phos- 
phate of lime was precipitated in the vat b by 
the gaseous ammonia, and the wash-waters, 
consist of chloride of ammonium, together 
with a moderate amount of chloride of cal- 
cium, in aqueous solution ; for it is in the 
act of combining with the gaseous ammonia 
that the hydrochloric acid which held the 
phosphate of lime in solution drops the latter 
as a solid precipitate. 

The preparation which this mother-liquor 
requires, therefore, to become serviceable 
again for its original service as ammonia 
material, is the very simple one of reduction 
to a small volume in the evaporating-pan 
(Plate 13). In this way the liquor may be 
reduced by heat to a dry crystalline mass, or 
relieved of only a part of its water, as may 
be desired. The residue in either state is 
ready for charging the generator, as already 
explained, and will thus serve over and over 



198 PURE FERTILIZERS. 

aeain an indefinite number of times, and with 
little or no loss if the manipulations are con- 
ducted with proper care. 

To return to the generator, if the contained 
charge of lime has not been wholly utilized 
at the time that the precipitation of the 
liquor in one of the vats b is completed, then 
the current of ammonia gas must be turned 
into another vat kept charged with fresh 
liquor for such a contingency. 

When, however, sufficient chloride of am- 
monium has been added to convert all the 
lime into chloride of calcium, — for the lime 
sends off the ammonia by seizing upon the 
hydrochloric acid with which the latter is 
combined, — the generator is to be emptied 
preparatory to receiving a new charge of lime. 
This is an easy matter when chloride of am- 
monium has been the ammonia material, for 
the residue is a liquid mush which will pass 
readily out through the sliding door in (Plate 
17), into a suitable reservoir through a gutter 
properly inclined, and communicating be- 
tween these two vessels. 

This mush consists of two portions, a 
liquid or solution of chloride of calcium in 



PHOSPHATE OF LIME. 199 

water, and a solid comprising the foreign 
matters of the lime. After repose the latter 
settle, and the former may be drawn off into 
a reservoir specially provided for its storage 
and subsequent utilization, as taught in 
Chapter xi. 

The Purge Liquor. 

At this time, that other portion of the chlo- 
ride of calcium obtained in the first step of 
the process from the carbonate of lime por- 
tion of the mineral, and known as the purge 
liquor, is to receive attention. It is an 
aqueous solution of chloride of calcium, con- 
taining some little iron and alumina, with 
more or less of phosphate of lime ; for it is 
only by exceptional care that some little of 
the latter can be prevented going into solu- 
tion during the purging operation. How- 
ever little, it must be reclaimed by adding 
very thin milk of lime with such caution that 
no excess may be used, to which end the ad- 
dition must be discontinued as soon as the 
liquor ceases to redden a blue litmus paper. 
On repose, all the phosphate of lime will 
settle, and carry along all or most of the iron 



200 PURE FERTILIZERS. 



and alumina with which it may have been 
associated in the purge liquor. Then, after 
the supernatant liquor of pure chloride of 
calcium has been drawn off into the storage 
reservoir, as above mentioned, for treatment 
according to the instructions of Chapter xi, 
the precipitate is to be washed with one or 
two fresh waters, next transferred to the 
drainers, Plate 23, and finally mixed with 
the previous chief portion in the drying-kiln 
or pug-mixer. 

If care has been taken in the first instance 
to wash the raw mineral well and to dry the 
precipitate thoroughly, the product will be a 
soft, nearly white powder, containing as much 
as 96 to 97 per cent, of pure phosphate of 
lime in the most sensitive condition, chemi- 
cally and agriculturally speaking ; so that, 
whether it be used as a direct fertilizer, or for 
conversion into superphosphate, the result 
will be, in the first case, a rich harvest ; and, 
in the second, a product of maximum strength 
and excellence. It is also as economical and 
convenient a material for the manufacture of 
phosphorus. 

The liquor in the extra cistern /, as soon 



PHOSPHATE OF LIME. 201 

as it has received ammonia enough to preci- 
pitate its phosphate of lime, is to be trans- 
ferred to the filtration vat b, and then drained 
and washed in the manner explained already 
at p. 193, as it corresponds exactly in com- 
position with the liquor therein treated. 

As soon as a vat is emptied of its saturated 
contents, it must be charged anew with a fresh 
portion of the hydrochloric solution of the 
raw mineral. 

All of the iron vessels employed should be 
coated with stearic pitch, in order to protect 
their surfaces against the corrosive action of 
the acid liquors. 

By having a battery of four precipitation 
vats, two of them may be kept in continuous 
operation, and one ammonia generator will 
serve for the entire series. 

As the form of these vessels is circular, 
and the thickness of the casting is not less 
than an inch even in the upper parts, each 
vat might be filled safely with liquor, as its 
strength will bear a pressure of 133 pounds 
to the square inch. 

Each vat of 18 feet height and 7 feet di- 
ameter, has a containing space of 693 cubic 



202 PURE FERTILIZERS. 

feet, which is equivalent to 4300 imperial 
gallons ; and may be made to complete an 
operation every ten or twelve hours. At two- 
thirds full, therefore, a vat will hold acid 
liquor representing about 6 or 7 tons of 
South Carolina Phosphate, and the battery 
described will give a daily product of, say, 12 
to 14 tons of pure precipitated phosphate of 
lime. 

In like manner, the single generator will 
hold materials enough at each charge to pre- 
cipitate the second fractional acid liquor of 
16 tons of " South Carolina Phosphate". 



CHAPTER IX. 



ON THE MANUFACTURE OF COLOMBIAN 
PHOSPHATE OF LIME. 

The precipitate obtained by this process con- 
tains a variable quantity of di-phosphate in 
association with tri-phosphate of lime ; and 
owing to its similitude in respect of com- 
position to the Colombian Rock Guano of 
earlier renown, I have distinguished it by 
the special designation of Colombian Phos- 
phate. It is very sensitive to the solvent in- 
fluences of the soil, and has the additional 
great advantage of requiring much less of 
sulphuric acid for its entire conversion into 
<5/-phosphate, than any other known product 
except the di-phosphate of lime. 

Moreover, this process is self-compensating 
throughout to the utmost possible degree ; 
that is, all the chemical agents employed in 
the refining operation are reclaimed in forms 



204 PURE FERTILIZERS. 

which have a market value equalling at least 
their original cost and expenses. 

For the sake of convenient manipulation 
and regularity of products, the manufacture 
should be conducted as much as possible 
with mineral of uniform composition and 
character. This, however, is by no means 
indispensable, as the process is able to bring 
out pure products from mineral phosphates of 
even poor and complex nature. 

''South Carolina Phosphate" will be made 
the example in these instructions. 

First Process. 

An indispensable preliminary step is to 
have analysed the raw mineral phosphate of 
lime about to be subjected to treatment, in 
order that its components may be exactly and 
quantitatively defined. Without such infor- 
mation it would be impossible to apportion 
the acids and other chemical agents, for 
its treatment, with anything like precision. 
The sample for analysis will represent more 
surely a fair average of the material, if it is 
taken from the whole mass of the latter after 
it has been powdered. Every separate in- 



COLOiMBIAN PHOSPHATE OF LIME. 205 

voice of mineral should undergo this chemi- 
cal scrutiny, as frequently the same source 
gives mineral of variable composition. As 
the operation must continue uninterruptedly 
during both night and day, a double set of 
hands will be required to relieve each other 
alternately. 

The first step is to grind the crude mineral, 
and then roast the fine powder in a reverber- 
atory furnace. This calcining operation re- 
duces the solubility of the iron constituents 
to the minimum ; and not only economises 
acids subsequently, but enhances the purity 
of the refined product. The carbonate of 
lime also loses a portion of its carbonic acid, 
and thus will produce less effervescence in 
the subsequent stage of digestion. Some- 
times, however, when a large amount of or- 
ganic matter has been present, there is formed 
a soluble carbonaceous matter which inter- 
feres, more or less, with the digesting and 
settling operations. 

The calcined mineral is now to be brought 
in wheel-barrows to the foot of the digestion 
vat (Plate 8), and it is then to be thrown into 
this vat, shovelful at a time. Previously, 



2o6 PURE FERTILIZERS. 



however, the vat must have been charged 
with the requisite weight of hydrochloric acid 
of specific gravity riyo. The proper ratio 
of this acid is i '00 to every i -00 by weight of 
" South Carolina Phosphate". 

To save the time and trouble of weighing 
the acid at every operation, the vat should be 
gauged and have chiselled down one of its 
sides a scale with divisions indicating one 
hundred pounds for each. 

The mineral is shovelled into the acid until 
the disengagement of carbonic acid produces 
so much effervescence as to cause an uprising 
of the mixture to near the top of the vat. 

After a brief delay, and as the intumescence 
subsides, more of the powdered mineral is to 
be added ; and so on, this manipulation is to 
proceed until the vat is charged to its full 
capacity. When all has been added, the work- 
man must distribute the solid mass over the 
bottom of the vat by means of a strong 
wooden rake. This done, and all the carbonic 
acid having been eliminated and allowed to 
pass off into the air, the covers are lowered, 
so as to close the top of the vat, and steam 
is let moderately into the tubes which dip 




COLOMBIAN PHOSPHATE OF LIME. 207 

into the vat or heat the surrounding air- 
chamber, in order that digestion may com- 
mence actively. 

The covers confine the vapours, prevent 
the volatilization of acid, and promote the 
chemical action ; but they must be raised oc- 
casionally, in order that the workman may 
rouse the solid matter from the bottom with 
a strong wooden stirring pole or rake. 

The mode of bringing the acid and powdered 
mineral in contact, as just described, is that 
which I followed in my experimental opera- 
tions ; and though it has many advantages, 
it is quite probable, especially on the score of 
convenience, that the use of the elevator and 
mixer would prove the best means. The 
manipulation to be followed with these latter 
has been described already in Chapters v 
and VIII. 

In about twelve to twenty- four hours all the 
carbonate and phosphate of lime, with some 
alumina and oxide of iron, will have been dis- 
solved, and then the heating is to be discon- 
tinued and the solution allowed to settle. 
When, after half an hour of repose, the hy- 
drochloric acid solution rests clear, as the 



2o8 PURE FERTILIZERS. 

upper stratum in the vat, it is to be drawn off 
by means of Blair's syphon (fig. 3) into the 
monte-jus (Plate 10). 

The solid residue consists of the valueless 
constituents of the raw mineral, but may still 
retain some traces of phosphates. Therefore, 
about 0*30 of fresh hydrochloric acid for 
every pound of South Carolina Phosphate is 
to be added, and the digestion renewed for 
several hours. Boiling water is now to be 
let in from a reservoir until the contents of 
the vat are doubled in volume, the whole 
stirred, and then left to repose. After half an 
hour, when the solid matters have settled, 
the clear supernatant liquor is to be drawn 
off into the monte-jus as before, by means of 
the syphon, to mix there with the previous 
strong liquor. 

The residue is next to be thoroughly 
washed. This is done by letting in its 
volume of boiling water, stirring, leaving to 
repose, and drawing off the clear liquor from 
the settling as before. This washing is to 
be repeated with fresh water, and then the 
residue is clean. The two wash-liquors must 
be mixed with the preceding strong liquors 
in the monte-jus. 



COLOMBIAN PHOSPHATE OF LIME. 209 

The insoluble residue comprises the or- 
ganic matter, sand, silica, and most of the 
alumina, oxide of iron, and fluoride of cal- 
cium, of the original or raw mineral, and 
must now be removed from the vat to give 
place to a new charge of fresh mineral. 

The total of acid prescribed is rather more 
than the equivalent proportions for the car- 
bonate and phosphate of lime constituents of 
the mineral ; but the slight excess is to pro- 
vide for the contingency of some of the 
aluminium and iron oxides being dissolved. 

To be assured that the washed residue is 
exhausted of phosphate, the following test 
must be applied : — 

Heat a portion, with hydrochloric acid, in 
a beaker glass for half an hour ; add some 
distilled water, and then filter. Reject the 
filter, but add aqua ammonias to the filtrate 
until the latter is barely neutralized ; after 
which, pour in an excess of oxalic acid, and 
filter. To the filtrate add an excess of aqua 
ammoniae, and filter. The filtrate will now 
contain phosphate ammoniae if there was 
any appreciable quantity of phosphate of 
lime or magnesia retained in the residue of 

p 



210 PURE FERTILIZERS. 

the digestion vat. To determine this point 
it remains only to add to the filtrate some 
little of a solution of chloride of magnesium, 
and a precipitate or cloud will be formed at 
once if the presence of phosphoric acid is 
in material degree. 

The united liquors in the monte-jus are 
next to be raised therefrom to the precipi- 
tation vat, as explained at p. 126. 

This liquor is a hydrochloric solution of 
phosphate of lime, containing chloride of 
calcium with some aluminium and iron chlo- 
rides. The vat may be filled to two-thirds 
of its capacity with this liquor, which then is 
to be brought to boiling by means of the 
steam-pipes provided for the purpose. These 
pipes should be of enamelled rather than 
plain iron ; for, though the first cost of the 
former is higher, it is stationary ; while that 
of the latter accumulates constantly by cor- 
rosion in the liquor. Moreover, as the iron 
pipes become rusted, they dirty both the 
liquor and precipitate ; whereas, the normal 
colour of both of these latter is white. 

As soon as the liquor has reached the 
boiling point, finely powdered whiting (levi- 



COL MB I A N PHOSPHA TE OF L I ME. 2 1 1 

gated chalk) is to be sifted into it very gradu- 
ally, and during constant steaming. Carbonic 
acid is disengaged at once from the whiting, 
which is a carbonate of lime, and there is 
much effervescence. At the same time, the 
hydrochloric acid is neutralized, and the 
phosphate of lime precipitates as a white mass, 
together with some alumina and oxide of 
iron. The liquor which it leaves above is 
wholly an aqueous solution of chloride of 
calcium. An excellent sifting arrangement 
is shown in elevation and plan by Plate 20. 
It consists of a wrought-iron frame-work a, 
running along the centre of the precipitation 
vat, and working on the rollers b, carried by 
the iron standards b , fixed to transverse 
timbers 0, extending from side to side of the 
vat. This frame-work carries a series of gal- 
vanised cast-iron boxes c, held securely by 
the screw-arrangement e. 

The distances between the boxes are about 
one foot. The sieve portion /^ is a thick 
zinc plate, finely perforated and rendered 
movable by the set screws g, in order that 
it may be taken out for cleaning when neces- 
sary. 

p 2 



212 PURE FERTILIZERS. 

The boxes are receptacles for the whiting. 
The driving power must be steam. Motion 
is communicated by means of a disc //, an 
axle /, and pulleys k. The disc has eccentric 
depressions / and elevations ;//, upon one of 
the sides. The two bars that form the frame- 
work a unite in one bar at ;/, and this, when 
the axle is revolving, follows, necessarily, the 
sinuosities of the wheel, and, as a conse- 
quence, draws the sieve backwards and for- 
wards. This shaking motion promotes the 
passage of the finer portions of the powder 
through the perforations after the manner of 
hand-sifting, but in a much more rapid and 
regular progression, p shows one side of the 
vat to which this sifter is fixed, r the support 
for the axle 2, and s the handles by which to 
lift the boxes when they are to be removed 
for any purpose. In order to prevent any 
contamination of the precipitate with an ex- 
cess of whiting, care must be observed to 
add the latter in gradual portions and to wait 
always for the effervescence from a previous 
dose to subside before adding a new or suc- 
ceeding portion. The approach of the neu- 
tral point makes itself evident, therefore, by 



COLOMBIAN PHOSPHATE OF LIME. 213. 

the effervescence becoming imperceptible as 
the last portions of whiting are added : or, 
in other words, when the addition of a little 
whiting to the boiling liquor ceases to cause 
a hissing and foaming of the latter, all of the 
phosphate of lime has been precipitated. 

The liquor clears rapidly when the point 
of neutralisation is reached. The two more 
important precautions to ensure success in 
this precipitation is to have the liquor in a 
sufficient state of dilution and at a high 
temperature as prescribed. 

When the operation, therefore, has been 
carried through according to the directions 
already noted, the precipitate will be all down 
chemically in a few hours ; and then the 
whole is left to repose. Shortly afterwards 
the precipitate will have settled mechanically, 
and the clear mother liquor above is to be 
drawn off into the wash-v2X or monte-jus 
placed beneath, for treatment according to the 
instructions in Chapter xi. 

As it is possible that the precipitate may 
contain some little caustic or carbonate of 
lime, notwithstanding the precaution against 
adding an excess, there should now be poured 



214 PURE FERTILIZERS. 

Upon it some dilute hydrochloric acid. This 
is best done by letting in fresh water, then 
heating by steam and adding the acid cau- 
tiously so long as there is any effervesence. 
Afterwards the steaming is to be stopped, 
and the whole allowed to settle. By this 
washing with acid the precipitate is freed ab- 
solutely from all traces of carbonate of lime ; 
but as some little phosphate of lime may be 
taken up, also, at the same operation, the 
supernatant solution must be preserved. It 
is to be drawn off, therefore, into the pre- 
cipitation-vat for treatment with the next 
strong liquor, instead of being sent into the 
wash-N2X. 

A much surer way, however, to avoid any 
excess of whiting is to bring the liquor to 
boiling by means of steam currents, and to 
add cautiously a thin milk of lime, in suffi- 
cient quantity to neutralise any free hydro- 
chloric acid. As soon as the milk of lime 
ceases to dissolve, and leave the liquor clear 
— that is when it produces a permanent 
cloud — then the whiting is to be added in 
the manner already prescribed, and in quan- 
tity barely equivalent, chemically, to the 



MORFIT on theJIanufactare ofFeitl 



Carrs' Mixing Mach 



FIG. I 



ate I'l-. 




jpeCxally df-'oigned fw D'' Morf jfs Vi/aric'oR f ertiLiZf^i-s . 



60,Pataiii"'2"j 



COLOMBIAN PHOSPHATE OF LIME. 215 

phosphate of lime in the liquor. When all 
is in, the boiling is to be continued until 
the liquor becomes a thick mush ; and to 
promote this change the precipitation vat 
must be provided with close steam tubes on 
the bottom, as explained in the following 
Chapter. Water is now added to wash the 
precipitate in the usual manner, and the 
decanted mother and wash liquors reserved 
for further treatment. The washed precipi- 
tate is to be dried on the bed of the kiln. 

By using a little less of whiting than is 
equivalent to the amount of tri-phosphate of 
lime in the acid solution, nearly all of the 
iron and aluminium, oxides and phosphates, 
will be left in the mother liquor. But, at 
the same time, some little of phosphate of 
lime may be retained with them. 

This liquor on being concentrated by 
evaporation will be a very effectual and pro- 
fitable material for removing ammonia from 
gas, for defecating sewage, and for disinfect- 
ing purposes generally ; as the changes as- 
sumed, in such chemical operations, would 
add to its agricultural advantage and money 
value. 



MOHl'IT on thr-Mann/ax-larc of Fertilizer. 



I'lul,. 



Carrs' Mixing Machine Detaii Side and front Elevation Sectional 



FIG.2. 




Hfat-tJ U ul^t. 



'^^-iilb: JlvJi'll.^i 1.11 ly^Morfits WoWt on t'eniUzeis. 



V iiv =ri Bix*is DayiScn. LA 



TriihncriC?.60.P^' 



2i6 PURE FERTILIZERS. 

At the same time, if it is desired to re- 
claim the small amount of phosphate of lime 
from the mother liquor, it can be done by 
adding thin milk of lime to the latter until 
it blues a red litmus paper. The lime neu- 
tralises the hydrochloric acid, and, as a con- 
sequence, the phosphate of lime which it 
retains in solution falls with the iron and 
aluminum compounds as a precipitate. This, 
on being washed and dried, may be sold as 
an inferior manure, or as material for 
Spence's and Townsend's processes, described 
in Chapters xix, xx, and xxi. The liquors 
left by this precipitate are to be utilised as 
directed in Chapter xi. 

If the precipitate in chief is to be sold as 
such, that is as Colombian Phosphate of 
Lime, enough of sulphate of ammonia or 
sulphate of potassa should be added now to 
convert the retained traces of chloride of cal- 
cium into sulphate of lime, and render the 
product free from humid tendency and per- 
manently dry. For this purpose the mass is 
steamed during the addition of the alkaline 
sulphate, and for some fifteen minutes after- 
wards. The mixture is then to be run into 



COLOMBIAN PHOSPHATE OF LIME. 217 

the basin of the kiln, and there dried for 
market as explained at p. 130, and by 
Plate 12. The product will be a nearly 
white powder having the following approxi- 
mate composition per cent. 

Tri-phosphate of lime - - So'OO to 85'00 

Di-phosphate „ - - 14-50 to lO'OO 

Ammonium or potassium cliloride - -60 to :8o 

Sulphate of lime _ _ _ -goto -95 

Aluminium and iron oxides and phosphates 2-oo to 2'25 

Water, accidental - . _ 200 to roo 



lOO'OO to lOO'OO 

On the other hand, should the precipitate 
be intended for conversion into superphos- 
phate, then it must be steamed while wet, 
with fresh water, for a few minutes, and after- 
wards left to repose. The clear liquor which 
thus rises to the top must be drawn off into 
the wash vat. This washing is to be re- 
peated twice in like manner, and the liquor 
run off each time into the wash vat. 

It is all-important to the convenience and 
economy of the subsequent operations (Chap- 
ters XIII, XIV, and xv) that the precipi- 
tated phosphate should be free from chloride 



21 8 PURE FERTILIZERS. 

of calcium, and hence the necessity of this 
thorough washing. 

The quantity of whiting required will de- 
pend upon its state of dryness, which is vari- 
able, and also on the quantity and strength 
of the acid liquor. These data will have to 
be determined by gauging the total volume 
of the liquor, and testing a fluid ounce as 
follows : In round numbers there must be 
enough to neutralise all the hydrochloric acid 
employed in making the solution of the raw 
mineral, except the equivalent proportion be- 
longing chemically to the carbonate of lime, 
iron, and alumina constituents. Therefore, to 
the test portion of one fluid ounce add aqua 
ammonise in slight excess ; filter (fig. i8) and 
wash. Reject the filter, but heat the filtrate in 
a beaker glass and on a sand bath, until all 
excess of ammonia has been volatilised. 

This filtrate is now to be treated very 
carefully with a normal nitrate of silver liquor 
just to that point when a cloud or preci- 
pitate ceases to be formed. The normal 
liquor is to be contained in one of Mohr's 
graduated burettes (fig. 4) with its india-rub- 
ber tube and spring clamp, a b, for regulat- 
ing the flow of its contents. 



COLOMBIAN PHOSPHATE OF LIME. 219 



The number of cubic centimetres of normal 
liquor consumed for the purpose indicates 
the quantity of dry hydrochloric acid in 
the filtrate. 




Fig. 4. 



One cubic centimetre of the normal liquor 



220 



PURE FERTILIZERS. 



should contain 0-467 grain of solid nitrate 
of silver to be equivalent to o*i grain of 
dry or gaseous hydrochloric acid (HCl). 
Therefore, this normal liquor is made by 
simply dissolving 467-0 grains of solid, 
pure nitrate of silver in enough of distilled 
water to make one litre at 60"^ to 62° F. A 
suitable flask with a litre mark a graduated 
on its neck, is shown by fig 5. Every 0.3425 




Fig. 5- 



of gaseous hydrochloric acid (HCl) is equiva- 
lent to I'D of liquid acid of specific gravity 
1-17 ; and requires, therefore, for its neutra- 
lisation 3-42 cubic centimetres of the normal 
test liquor. 



COLOMBIAN PHOSPHATE OF LIME. 221 

The Mother-Liquor or Wash. 

Attention is now to be turned to the 
mother-liquor or wash from which the phos- 
phate of lime was precipitated. It is wholly 
an aqueous solution of chloride of calcium 
from the carbonate and organate of lime of 
the original raw mineral and the lime base 
of the whiting. 

As the volume will be large, the better 
way would be to evaporate it to a solid form 
and sell it as material for Ransome's artifi- 
cial stone. For this purpose, it is to be run 
into iron barrels while still in a fused state, 
and there allowed to set hard. The barrels 
have each a capacity of one-fifth of a ton. 

A form of evaporating furnace, which will 
answer for this liquor, may be found in the 
salt manufactories, where there is a great ex- 
perience in such operation. 

There is already a considerable demand 
for solid chloride of calcium in Great Britain 
and the United States of America, by those 
parties who are working the patented process 
aforesaid, for the manufacture of artificial 
stone. 



222 PURE FERTILIZERS. 

The presence of some chloride of alumi- 
nium would not be injurious for this purpose. 
On the contrary, in my opinion, it would be 
beneficial, and might be added advantage- 
ously. 

The precipitation of the wash-liqtior by 
milk of lime will clear it of both alumina and 
oxide of iron. If gas-liquor or the sulphates 
of ammonia and potassa are accessible at 
moderate cost, then it would be advisable to 
convert a part of the wash-liquor into alkaline 
chloride, as explained in Chapter xi. 

Second Process. 

I have worked out recently another method 
which has important advantages over the 
one just described. It not only delivers the 
phosphate of lime in a pure state, but uti- 
lizes, as precipitant, the iron and aluminium 
compounds with which the former is naturally 
associated in the crude mineral. 

The process is carried out by digesting the 
finely powdered rock guano or other mineral 
phosphate of lime in a suitable vat with 
enough hydrochloric acid to dissolve out all 
of its soluble matter. The solution is then 



COLOMBIAN PHOSPHATE OF LIME. 223 

drawn off from the insoluble residue and 
treated in a separate vat with enough of the 
iron and aluminium compounds of the raw 
mineral to precipitate all of the phosphate of 
lime. The heating and stirring during this 
manipulation are to be accomplished by 
means of steam-currents entering the liquor. 

The iron and aluminium compounds are 
to be added gradually in the form of a pulp 
until a precipitate ceases to fall. A sample, 
tried in a test-tube, from time to time, will 
indicate this point. A few hours of repose 
are now to be allowed. 

All of the phosphate of lime is thus thrown 
down as a white powder ; while the liquor 
above contains all, or nearly all, of the iron 
and aluminium compounds of the original 
raw mineral in hydrochloric solution. This 
latter, or '* mother-water", is a most advan- 
tageous substitute for '* Alta Vela Guano" in 
the defecation of sewage. 

The settled deposit of pure Colombian 
phosphate of lime is to be washed with seve- 
ral relays of fresh water and dried at or be- 
low 212° F., for market; or mixed as pulp 
with the requisite equivalent of sulphuric 



224 PURE FERTILIZERS. 

acid, in a pug-mill, and converted into a high 
grade of " superphosphate". 

The ''mother-liquor" is a mixture of chlo- 
ride of calcium and hydrochloric solution of 
iron and aluminium compounds. On the 
addition to it of a sufficient quantity of milk 
of lime to make the liquor turn blue a red 
litmus paper, the whole of these iron and 
aluminium compounds are precipitated. By 
repose, they settle well at the bottom, and 
then the supernatant liquor is to be drawn 
off. 

The precipitate, after having been washed 
and pressed, is ready for use or sale. A part 
of it is to serve as precipitant for the succeed- 
ing batch of mineral solution ; and the re- 
mainder will be a most advantageous substi- 
tute for the mineral phosphates of alumina in 
the manufacture of alum, phosphorus, phos- 
phoric acid, and the phosphates ; in the refin- 
ing of sugar ; in the defecation of sewage ; 
and for other useful purposes. 

This pulpy precipitate is a mixture of iron 
and aluminum oxides and phosphates, and 
will effect the precipitation, whichever of its 
components may predominate. In other 



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COLOMBIAN PHOSPHATE OF LIME. 22t, 

words, by this method, the oxides and phos- 
phates of iron and aluminum, whether natu- 
ral or prepared artificially, will serve singly 
or jointly for precipitating the phosphate of 
lime constituent from acid solutions of 
mineral or crude phosphates. 

The pulp required for an inaugural opera- 
tion is to be obtained by means of milk of 
lime from the mother liquors of the preced- 
ing process, or from that of the first di-phos- 
phate method in the next chapter. 



CHAPTER X. 



THE MANUFACTURE OF DI- OR NEUTRAL- 
PHOSPHATE OF LIME : AND OF CHLORO- 
PHOSPHATE OF LIME. 

This salt of lime deserves the best consider- 
ation, alike of manufacturers and consumers. 
It contains a higher ratio of phosphoric acid 
than the tri-phosphate. Hence, less of sul- 
phuric acid is required for its conversion into 
bi-phosphate, and it gives a more concen- 
trated product. For this same reason, it is a 
most advantageous basis-material for the 
manufacture of phosphorus. 

Though not directly soluble in water to 
any great extent, the di-phosphate is, never- 
theless, a most active and economical ferti- 
lizer ; for the chemical and atmospheric in- 
fluences of the soil split it promptly into 
soluble modifications which nourish a grow- 
ing crop as vigorously as would the bi-phos- 



DI-PHOSPHATE OF LIME. 227 

phate. It is only the prejudice born of 
familiarity in the use of the bi- or superphos- 
phate, and of a want of experience with the 
di- or neutral-phosphate, that blinds the 
popular eye to the greater economy and 
equal potentiality of the latter as a manure. 
But, as time extends its production and 
brings it forward more abundantly into mar- 
ket, this di-phosphate will become better 
known and secure that appreciation which 
will give it a first place among fertilizers. 

The successful manufacture of this article 
is founded upon the studies of T. J. Way, 
Deligny, and myself, who are the only 
chemists from whom the subject has received 
any serious practical consideration. 

As the chemical characters of this di- or 
neutral-phosphate of lime have been de- 
scribed already at page 71, I will proceed at 
once to explain the methods of preparing it 
in a commercially pure state. 

Morfifs Process (A). 

Having selected a mineral or other crude 
phosphate of lime of uniform composition 
and reduced it to powder, the next step is to 

Q 2 



228 PURE FERTILIZERS. 

add to it sufficient hydrochloric acid of 
specific gravity riy to dissolve out the car- 
bonate and organate of lime constituents. 
This is called the purging operation. If the 
raw mineral should contain any fluoride of 
calcium, the cover of the digester must be 
fitted with a flexible-joint pipe leading into 
the chimney for the purpose of conveying 
away the fumes. 

The acid may be diluted advantageously 
with water, and the purging manipulations 
should be performed with the aid of an eleva- 
tor and mixer, as described at pp. 111-115. 
The carbonic acid is thus got rid of more 
quietly and conveniently than if the powder 
and acid were mixed in mass. 

When all of the powder and acid has fallen 
from the mixer into the digesting vat (Plate 
8), more hydrochloric acid must be added, 
and the whole well heated and stirred, as ex- 
plained at p. 207. 

The proportion of hydrochloric acid neces- 
sary to complete a digestion, will be the com- 
bined chemical equivalents of the carbonate 
of lime, organate of lime, tri-phosphate of 
lime, and iron and aluminium compounds 



DI-PHOSPHATE OF LIME. 229 

contained in the raw mineral, and must be 
calculated according to the analysis of the 
latter and the data stated already in preced- 
ing chapters. 

But, after the purging operation, for the 
removal of the carbonate and organate of 
lime, the mineral mass should be treated 
with the remainder of the acid in divided 
portions or moieties. That is, the digestion 
should be continued with one-half of the 
residual acid as a second step ; and w^hen 
this latter has become charged with soluble 
matter, it is to be diluted with water, heated 
by the '' blow-tip\ allowed to settle, and de- 
canted or drawn off. 

After this decantation through a tap or by 
means of a syphon, the last moiety of fresh 
acid is to be added, and the digestion con- 
tinued. When the insoluble residue seems 
to be exhausted, water of dilution is to be 
poured in again, and the whole heated by a 
''blow-up'' and allowed to settle, as pre- 
viously. The clear liquor is then to be 
drawn off, and the residue washed with seve- 
ral relays of fresh water, by means of the 
" blow-tip\ in like manner. The sand and 



230 PURE FERTILIZERS. 



silicates, etc., forming the insoluble residue, 
are to be removed from the digester and 
thrown out as valueless waste ; the strong 
and wash-liquors are to be united in the 
precipitating vat. 

Before passing, however, to the precipi- 
tating operation, it is expedient to record a 
few notes respecting the choice of a digesting 
or solution vat for the raw mineral. 

In many mineral phosphates the presence 
of large ratios of insoluble residuum and 
organic matter cause the powder to form a 
thick mass with the acid, and this impedes 
the digestion. In such cases, the " blow-up' 
w^ould have to be used frequently, or even 
constantly, in gentle current, so as to supply 
the proper state of dilution by means of con- 
densed steam. This may cause such a con- 
densation of steam as to dilute the liquor 
excessively, and weaken its solvent power. 
Keeping the digester constantly covered 
during the operation, as is obligatory, to 
prevent the volatilization and loss of acid, 
will not hinder the excessive dilution, but 
rather promote it. If the raw mineral is 
easily soluble, this dilution will be imma- 



DI-PHOSPHATE OF LIME. 231 



terial ; but there are many kinds of rock or 
fossil phosphate of lime which resist, with 
much obstinacy, the solvent action of even 
strong acids. In these latter cases, then, the 
double vat with surrounding hot-air chamber 
will be required for the operation of digest- 
ing them. The means of heating being a 
surrounding hot-air chamber, the ''blow-tip'' 
of open steam need not be used except for 
rousing the mass occasionally. 

Time, too, is an important element in the 
digesting operation ; for, while some of the 
mineral or fossil phosphates of lime give up 
all their soluble matter in six hours, others 
require twice, thrice, and even fourfold that 
time for their solution. 

The combined liquors in the precipitation 
vat, representing the soluble matter of the 
crude mineral, are an aqueous solution of 
chloride of calcium, containing a hydrochlo- 
ric solution of tri-phosphate of lime, together 
with iron and aluminium compounds. 

The vat may be of cast or wrought iron, 
coated with stearic pitch, and according to 
the form, dimensions, and general construc- 
tion shown by Plate 1 1 . But at the bottom 



232 PURE FERTILIZERS. 

there must be a bed of closed iron tubes 
for the circulation of steam, in order to form 
a broad extent of heating surface. The ex- 
terior of these tubes must be coated with 
Clark's enamel.* 

The liquor in the precipitation vat is to be 
brought to boiling by means of the ''blow- 
up', and then treated cautiously with very 
thin and strained milk of lime until all the 
free hydrochloric acid has been neutralized. 
This is known as soon as the lime ceases to 
dissolve and leave the liquor clear or free 
from cloud. 

After having reached this point, the liquor 



* I am now having a vat constructed which combines 
efficiency, durability, and cleanhness in an eminent degree. 
It consists of only five pieces of cast-iron, each six by four 
feet, so that a large vat is formed with only a few joints ; 
which are made tight by hard india-rubber slips and nut- 
screws. The interior surfaces of the plates, as well as the 
steam-tubes and bottom-coil, are enamelled with porcelain, 
so as to be proof against corrosion. To give strength, the 
plates have ribs cast on the outside in a manner to form 
spaces for the insertion of felt cloth and panel covers, for 
maintaining the heat of the contents of the vat. Vats thus 
made are inexpensive, comparatively, and serve equally 
well for digestions, precipitations, and evaporations, whether 
hot or cold. 



DI-PHOSPHATE OF LIME. 



-i5 



is to be treated further with a certain quan- 
tity of thin milk of lime containing only a 
little more of caustic or quick-lime than is 
equivalent, chemically, to one-half of the tri- 
phosphate of lime in the original raw mine- 
ral. Thus, if the latter, according to an ac- 
curate analysis, contained fifty per cent, of 
tri-phosphate of lime, and its digestion with 
hydrochloric acid has been conducted effectu- 
ally, the liquor from it will hold the entire 
quantity in solution ; and this will make a 
total of 1 1 20 pounds for every ton of raw 
mineral. Supposing, therefore, that one ton 
of the mineral be under operation, then the 
liquor for it will require o*i8 to 0*20 pound 
of pure quick-lime for the precipitation, as 
di-phosphate, of each and every pound of tri- 
phosphate of lime that it may contain. 

The lime must be added in the form of a 
thin milk and through a fine sieve, so that 
the passage of coarse particles or dirt may be 
intercepted. 

After all the lime has entered, the steam is 
to be turned off from the " blow-tif' into the 
closed tubular bottom, so that dry boiling 
and evaporation may go on regularly. As 



234 PURE FERTILIZERS. 

the mixture becomes concentrated it thickens 
gradually, and when it has reached a state of 
very sluggish fluidity it will assume, suddenly, 
the consistence of a thick paste. The heat 
must be continued from this period until the 
paste acquires a certain degree of dryness, 
and then it is to be drenched with its volume 
of fresh water, heated and stirred for a few 
minutes by means of the '' blow-tip\ and left 
to repose for eight or ten hours. 

The clear mother- liquor is now to be 
drawn off from the settled precipitate of di- 
phosphate into a large storage vat for treat- 
ment, as hereafter directed. 

The precipitate must be washed with seve- 
ral relays of fresh water, with the aid of the 
'' blow-tip' \ and after each settling the wash- 
water is to be drawn off as before, and mixed 
with the strong mother-water in the storage 
vat. The precipitate is then to be dried in 
the same vat by moderate currents of steam 
coursing through the tubular steam-heating 
coil at the bottom. 

If the precipitate, as such, is to be sent into 
the market, there must be added to it, during 
the drying operation, an aqueous solution of 



DI-PHOSPHATE OF LIME. 235 

one or more per cent, of sulphate of ammo- 
nia, in order to decompose any traces of 
chloride of calcium it may have retained, and 
remove thus the least possible tendency to 
dampness. 

Care must be observed not to over-heat the 
precipitate, otherwise its bright colour and 
solubility will be damaged. Therefore, the 
temperature, or rather the current of steam, 
must be diminished as soon as any sign of 
rusty appearance begins to show itself in the 
mass. With this precaution, the precipitate 
will be a beautiful white pulverulent mass, 
readily broken down by the back of the 
shovel, and is ready then to be packed in 
bags for market. 

Though the mother-liquor will show still 
an acid reaction when being drawn off from 
the settled precipitate, that is no indication 
of its having retained any tri-phosphate of 
lime. It is true that, by restricting the pro- 
portion of quick-lime precipitant, as directed, 
nearly all the iron and aluminium compounds 
are kept back in solution, but the precipita- 
tion of all the tri-phosphate of lime is as- 
sured if the manipulations are conducted 
properly. 



235 PURE FERTILIZERS. 

The mother-liquor, then, is a mixture of 
aqueous and hydrochloric solutions of chlo- 
ride of calcium and iron and aluminium 
oxides and phosphates. 

To determine whether any traces of phos- 
phate of lime are present, it is only necessary 
to add a few drops of lime-water to a small 
portion of the liquor, which, in that case, 
will give a white precipitate. If there is any 
bluish-grey or brown tint in the precipitate, 
it may be inferred that the latter consists 
wholly of iron and aluminium compounds. 

My experience proves that, with the quan- 
tity of lime which has been prescribed and a 
faithful performance of the stated manipula- 
tions, there is little or no phosphate of lime 
left in the mother-water. 

The precipitate, consisting chiefly of di- 
phosphate, which is the prime object of the 
refining process to which this chapter relates, 
may be rendered nearly anhydrous by push- 
ing the drying process to extremity. But, 
for the sake of its handsome appearance and 
more active solubility in the soil, it is expe- 
dient to send it into market merely as a 
powder of ordinary dryness. In this form it 



DI-PHOSPHATE OF LIME. 237 



retains water of constitution and some acci- 
dental moisture. 

To clear the mother-water of its iron and 
aluminium constituents and render it a pure 
aqueous solution of chloride of calcium for 
utilization, as directed in Chapter xr, thin 
milk of lime is to be added to it in a suitable 
vat until a red litmus paper, dipped therein, 
becomes blue. The above-named consti- 
tuents are thus precipitated, and after a re- 
pose of some minutes leave above a clear 
liquor of chloride of calcium, which is to be 
drawn off. The deposit is then washed with 
several relays of fresh water, drained, and 
pressed in cloths, or dried to powder in the 
kiln, according to the use for which it may 
be intended. 

If it is the product of a raw mineral which, 
like Cooperite or Navasa Guano, contains a 
very large proportion of phosphates of iron 
and alumina, then it may be reserved advan- 
tageously for the uses set forth in Chapters 
XIX, XX, and xxi. 

Dissolved in sulphuric acid, it becomes 
much superior to the "Alta Vela and Redonda 
Guanos" as a material for defecating sewage, 



238 PURE FERTILIZERS. 

and manufacturing purposes. In hydrochlo- 
ric solution it is an excellent disinfectant. 
As a dry powder it is a fertilizer of fair but 
comparatively inferior grade. 

Morjifs Process (B). 

This important modification of the preced- 
ing (A) method possesses novelty and many 
great advantages. In the first place it elimi- 
nates the iron and aluminium compounds 
usually present in the raw mineral phos- 
phates, and thus delivers the phosphate of 
lime constituent as a pure product. Secondly, 
it utilizes as precipitant the iron and alumi- 
nium compounds which it eliminates. 

This means insures uniform results with 
the least amount of labour and the greatest 
simplicity of operation. It removes the ex- 
pediency, too, of roasting the raw mineral 
previously to digesting it, as prescribed here- 
inbefore, for rendering the iron and alu- 
minium constituents insoluble. 

Indeed, when these latter are in large pro- 
portion and mostly as phosphates, they can 
be turned to profitable account as by-pro- 



DI-PHOSPHATE OF LIME. 239 

ducts. Hence, those highly alumino-ferru- 
ginous phosphates of lime, like " Navasa 
Guano" or " Cooperite", which are such ob- 
jectionable materials for the ordinary pro- 
cesses, become quite eligible in connection 
with this mode of treatment. 

The crude phosphate of lime having been 
selected, is to be powdered finely, and 
digested in a raw state with the requisite 
amount of hydrochloric acid. The propor- 
tion of the latter will depend upon the com- 
position of the former, as determined pre- 
viously by a careful analysis. There must 
be so much for the carbonate of lime con- 
stituent, an additional portion for the tri- 
phosphate of lime element, and a further 
quantity for their alumino-ferruginous asso- 
ciates. The data for calculation are given 
in the preceding chapters, and express the 
chemical equivalent ratios. 

The apparatus and manipulations are the 
same, also, as described for the (A) process 
just previously recorded. 

When the hydrochloric solution of the 
raw mineral, together with the wash waters 
from the latter, are in the precipitation vat, 



240 PURE FERTILIZERS. 

they are to be mixed and heated to boiling 
by means of the '' blow-up!' 

Previously, however, a stock or capital of 
the alumino-ferruginous compounds must 
have been accumulated by precipitating the 
mother waters of the previous process with 
milk of lime, after the separation of their 
phosphate of lime freight. 

It is only necessary to add thin milk of 
lime until the mixture in the vats turns blue 
a red litmus paper. A slight excess of 
lime is unimportant. The greyish blue or 
lead-colored precipitate which falls down is 
the desired material. It may contain, pos- 
sibly, some little phosphate of lime, but that 
is immaterial ; for it is one of the advantages 
of this process that its operation and 
economy are undisturbed, whether an excess 
or deficiency of the precipitant may have 
been used. All is brought right by the 
easiest of manipulations, as will be explained 
directly in the proper place. 

The precipitate, after repose, is to be re- 
lieved of the clear liquor of chloride of cal- 
cium which rests above it. This is drawn 
off through taps suitably placed, or by means 



DI-PHOSPHATE OF LIME. 241 

of a syphon, and economised as directed in 
Chapter xi. One washing with fresh water 
will now suffice for the precipitate, and it is 
to be accomplished by the aid of the " blow- 
ppr The wash water, after repose, is to be 
drawn off and mixed with the previous 
mother water. 

The precipitate, in its pulpy state, is ready 
now for use, as the precipitant of the hydro- 
chloric liquor obtained by digesting the raw 
mineral. 

This liquor consists of calcium, iron and 
aluminium chlorides, together with tri-phos- 
phate of lime, and iron, and aluminium 
phosphates in solution. It is to be brought 
to boiling by means of the '* blow-up^' 
and treated with the pulpy precipitate afore 
said by shovelfuls of the latter at a time. 
When the first portion is added it will not 
cloud the liquor if the latter is very acid ; 
but, as subsequent doses bring about the 
point of neutralization, a white precipitate 
begins to form. This is my Colombian 
phosphate of lime ; and when it ceases to be 
produced, the addition of pulp must be dis- 
continued. 



242 PURE FERTILIZERS. 

As the pulp is rather lighter than the acid 
liquor, it floats on or near the top, so that it 
can be observed readily, by the perfect solu- 
tion of a preceding dose when it is proper 
or necessary to supplement it with a succeed- 
ing one. 

In this way an excess may be avoided, but 
at the same time can be removed, when it 
occurs, by the mere addition of some fresh 
acid liquor. 

The alumino-ferruginous pulp, in neu- 
tralizing the hydrochloric acid throws down 
only the phosphate of lime. All of the other 
constituents of the raw mineral which may 
have been dissolved out during the diges- 
tion, will remain in the mother liquor ; and 
this latter, after repose, is to be drawn off 
from the subsident precipitate for treatment, 
as will be explained hereafter. 

Upon the precipitate is now to be poured 
a quantity of fresh acid liquor, equivalent to 
the original volume of that just thrown 
down ; and this relay must contain the same 
total of phosphate of lime as the first liquor. 
Steam is then let in through the " blow-7tf' 
for five or ten minutes, after which the heat- 



Dl-PHOSPHATE OF LIME. 243 

ing must be continued by means of the 
closed tubular coil at the bottom of the vat, 
until the mass evaporates to the consistence 
of a stiff, dry mush. Fresh water is then 
to be added, the whole mixed thoroughly 
by a current of steam through the " blow-iip^^ 
and allowed to rest. 

The precipitate which settles is di-phos- 
phate, containing more or less of tri-phos- 
phate of lime ; and the clear liquor above — 
to be known as the mother liquor — is a 
mixed solution of calcium, iron, and alumi- 
nium chlorides. Oftentimes, however, the 
alumino-ferruginous portion of the liquor 
may be chiefly phosphatic. 

The mother liquor is to be drawn off from 
the precipitate into a suitable vat or reser- 
voir ; after which the latter is to be washed 
with several relays of fresh water. The 
wash waters are in all cases to be mixed 
with the mother liquor. If the precipitate 
is to be converted into superphosphate, it 
should be taken directly after the washing, 
from the precipitation vat to the pug-mixer 
(PI. 21). 

On the other hand, when it is to be sent 

R 2 



244 PURE FERTILIZERS. 

into market as such, it should be heated 
after the last washing by means of the 
" blow-up^' with an aqueous solution of one 
or two per cent, of sulphate of ammonia, 
to destroy any hygroscopic tendency that 
may be retained through lingering traces of 
chloride of calcium. Finally, it must be 
dried on the kiln ; and then crushed to 
powder with the back of the shovel, or by 
means of Carr's disintegrator ; after which 
it is ready to be packed into bags for 
market. 

The quantity of alumino-ferruginous pulp 
which may be required will depend, not only 
upon its state of moisture, but also upon 
its chemical composition. That is, if the 
pulp is more oxide than phosphate, less 
weight will suffice for the precipitation, and 
vice versa. In my experience, the only prac- 
tical way of determining this point with 
precision, and quickly, is to test a small 
portion of the liquor, experimentally. 

Thus, a given volume of ten fluid ounces 
of the acid liquor is treated, while boiling, 
with the pulp, until precipitation ceases. 
From the weight, or even the bulk, of the 



DI-PHOSPHATE OF LIME. 245 

pulp consumed, may be estimated, with suf- 
ficient accuracy, the whole quantity which 
the total of the liquor in the vat will require. 

Of course, the entire volume of liquor 
must have been gauged previously ; and for 
this purpose it will be convenient to fix a 
permanent measure-rod to the interior side 
of the containing vat. 

The mother liquor and wash waters com- 
bined are an aqueous solution of calcium, 
iron, and aluminium chlorides, associated 
with hydrochloric liquor of alumino-ferru- 
ginous phosphates. Possibly, there may 
be present, also, some traces of phosphate of 
lime. This latter may be wholly separated 
by merely adding, with caution, only that 
quantity of alumino-ferruginous pulp which 
is necessary to precipitate it. 

The mother liquor, then, is an admirable 
means for defecating town-sewage, accord- 
ing to the methods explained in Chapter xx. 

But if its burthen of aluminium and iron 
compounds is large, then this must be sepa- 
rated and sold for the profitable purposes 
described in Chapters xix and xxi. Owing 
to its pulpy condition, it will be very soluble 



MOHII r Ml ihfM'iiuil.uliin I'/JWillix 




GROUND P LAN 



246 PURE FERTILIZERS. 

in acids, and, therefore, a much more de- 
sirable raw material than "Redonda Guano", 
" Alta Vela Guano", and kindred minerals. 
Moreover, it will have the great advantage 
of being a domestic by-product, free from the 
risks and expenses of importation. 

The only treatment necessary to separate 
it from the mother water is the addition of 
thin milk of lime until the liquor turns blue 
a red litmus paper. The precipitate which 
falls leaves above a pure solution of chloride 
of calcium, which is to be drawn off and 
utilized, as directed in Chapter xi. The 
precipitate, after one or two washings, with 
fresh waters, is to be drained or pressed in 
cloth, and barrelled for market. 

As the mother liquor, from the treatment 
of the first lot of mineral, will serve to 
furnish the pulpy precipitant by this treat- 
ment an indefinite number of successive 
times, it will be seen that only the first batch 
is required for an uninterrupted continuity 
of precipitating operations. The mother 
liquor will give back always the whole of 
the precipitant when prompted by the addi- 
tion of milk of lime. 



DI-PHOSPHATE OF LIME. 247 

There will be constantly, therefore, a daily 
recurring quantity of this by-product for the 
profitable applications set forth in Chapters 
XIX, XX, and xxi. 

y. Thomas IVays Process. 

My knowledge of this method is little 
beyond that which the specification of the 
patentee supplies. It, however, yields a 
handsome product in the form of a fine 
white powder, which has, according to 
Wanklyn's analysis, the following composi- 
tion, per cent. 

Hygrometric moisture - - - 2' 18 

Constitutional water _ _ _ 14-69 

Sand and matters insoluble in acids - - 9*24 

Sulphate of lime - - - - 2* 17 

Oxides and phosphates of iron and aluminium with ) 

a little of magnesia _ . J 

Lime - - 30*62 \ ^. . , , n- ^^ o 

_^, , . . , > Di-phosphate of hme - 66-83 

Phosphoric acid 3 3" 21 ) 

99"94 



"This invention relates to the production 
from ordinary phosphate of lime and the use 
for manure of a compound of lime and phos- 
phoric acid intermediate in composition and 



248 PURE FERTILIZERS. 

character between ordinary insoluble phos- 
phate of lime and acid or soluble phosphate 
of lime. By ordinary phosphate of lime I 
mean to express the phosphate of lime ex- 
isting naturally in bones, bone-ash, animal 
charcoal, and in the usual mineral varie- 
ties of this substance, and by acid phosphate 
or soluble phosphate of lime I mean that 
form of readily soluble phosphate of lime 
which is produced by the action of sulphuric 
acid on ordinary phosphate of lime, and which 
exists in the substances usually called 'super- 
phosphates'. The ordinary phosphate of lime 
first mentioned contains three equivalents or 
combining proportions of lime to each equi- 
valent or combining proportion of phosphoric 
acid, and contains lime and phosphoric acid 
in the proportion of lime 53'9, and phosphoric 
acid 46" I. I shall, for sake of convenience, 
call this tri-phosphate of lime, in reference to 
the three equivalents of lime it contains. The 
acid phosphate or soluble phosphate of lime 
contains only one equivalent or combining 
proportion of lime to each equivalent or com- 
bining proportion of phosphoric acid ; I call 
this mono-phosphate of lime, as containing 
only one equivalent of lime. It contains lime 
and phosphoric acid in the proportion of 28 
parts of lime and 72 parts of phosphoric 



DI-PHOSPHATE OF LIME. 249 

acid. Now, the compound of lime and phos- 
phoric acid, which is the subject of this in- 
vention, contains two equivalents or com- 
bining proportions of lime to one equivalent 
or combining proportion of phosphoric acid ; 
I therefore call this substance di-phosphate of 
lime, and it contains lime and phosphoric 
acid in the proportion of lime 43*8 parts, and 
phosphoric acid 56'2 parts. This compound 
is known by chemists to exist, and is de- 
scribed in some works on chemical science ; 
but it has not been made for practical use, 
nor by any of the methods about to be de- 
scribed, nor has it been used or proposed for 
use as manure, for which I have ascertained 
that it is well suited. For, whereas tri-phos- 
phate of lime, whether in its natural state or 
artificially produced, is not sufficiently solu- 
ble in water for purposes of vegetation, and 
the mono-phosphate or ordinary 'super-phos- 
phate' is so readily soluble in water that it is 
liable, in some cases, to be washed out of the 
soil by heavy rain, and so cause a loss of a 
valuable and expensive product, the di-phos- 
phate of lime is soluble to the extent of from 
15 to 25 grains only in a gallon of pure water, 
and to a larger extent in water containing 
carbonic acid ; it is, therefore, free from both 
the causes of objection above referred to, and 



250 PURE FERTILIZERS. 

its use for manure will be attended with great 
advantage and be found to be economical. 

" I have ascertained that di-phosphate of 
lime can be produced with sufficient economy 
to enable it to be practically used as a manure 
by the methods which I proceed to describe. 

" I. I take any form of tri-phosphate of 
lime, such as bone-ash, animal charcoal, 
coprolites, apatite, or phosphatic guano, and, 
having ascertained by analysis the proportion 
of carbonate and phosphate of lime in it, I 
add to it hydrochloric acid in such quantity 
as shall be sufficient to dissolve the carbonate 
of lime and also to unite w^ith one-third part 
or one equivalent of the three equivalents of 
lime contained in the phosphate of lime, avoid- 
ing the use of any considerable excess of acid 
beyond that mentioned above. I dilute the 
acid before employing it with as much water 
as shall have been found, by previous experi- 
ments, necessary to enable it to be mixed in- 
timately with the powdered phosphate, so that 
every portion may be well moistened ; and, 
in this mixing, I employ some suitable me- 
chanical arrangement, such as an ordinary 
pug-mill, used for mixing clay. I allow the 
mixture to rest until I find, by treating a small 
portion with cold water and testing the filtered 
solution by ammonia or lime water, that very 



DI-PHOSPHATE OF LIME. 251 

little phosphate of lime remains in solution. 
I find that a gentle temperature given to the 
mixture greatly promotes the production of 
di-phosphate; and I sometimes diy the mixed 
materials on hot plates or by other convenient 
arrangement, taking care that the heat does 
not exceed 250" Fahrenheit ; I then add cold 
water, and wash out the chloride of calcium, 
which is produced from the carbonate of lime 
and the J part of the lime of the tri-phosphate. 
The washed residue is the di-phosphate of 
lime in a state more or less pure, which I dry 
for use at a temperature which should not ex- 
ceed 240*^ or 250^ Fahrenheit. Before allow- 
ing the wash-water to run to waste I render 
it alkaline by lime, and by subsidence or fil- 
tration I separate and preserve the insoluble 
matter which will contain phosphate of lime. 
As a source of tri-phosphate in the foregoing 
process, I prefer to employ bone-ash, or ani- 
mal charcoal, or tri-phosphate artificially pre- 
pared. In carrying this process into effect the 
proportion of hydrochloric acid to be used 
will depend upon the proportions of phos- 
phate of lime and carbonate of lime with bone- 
ash, animal charcoal, or other phosphoric sub- 
stance or mixture of substances employed and 
the strength of the hydrochloric acid itself. 
If liquid hydrochloric acid of specific gravity 



252 PURE FERTILIZERS. 

1-145, and containing- about 30 per cent, of 
real acid, is used, it will require 240 parts by 
weight of such acid for each 100 parts of car- 
bonate of lime, and 76 parts for each 100 
parts of phosphate of lime present in the sub- 
stance or mixture of substances to be acted 
upon ; for instance, supposing that the crude 
phosphate contains 70 per cent, of phosphate 
of lime and 10 per cent of carbonate of lime, 
the quantity of acid of 30 per cent, to be added 
to each 1000 lbs. of such crude phosphate 
will be 240 lbs. for the carbonate, and 532 for 
the phosphate of lime, or together, 772 lbs. ; 
and so on, in relation to the varying propor- 
tions of the phosphate and carbonate of lime 
in different substances treated. As before 
mentioned, I find that the production of di- 
phosphate of lime is very much assisted by 
the application of a gentle heat to the mix- 
ture ; but I am careful to regulate the tem- 
perature, as, otherwise, the result of the 
action will be to produce the ordinary tri- 
phosphate of lime instead of the di-phosphate. 
I have named 250"^ Fahrenheit as a temper- 
ature which is both safe and sufficient for the 
purpose. This amount of heat may be ob- 
tained by hot plates, or ovens, or other ordi- 
nary means. When heat is to be employed, 
an excess of hydrochloric acid may be used 



DI-PHOSPHATE OF LIME. 253 



with advantage, but arrangements must be 
made to collect and condense the fumes of 
the excess of acid which will be driven off. 

" 2. I treat any mineral or other phos- 
phate with sufficient hydrochloric acid to 
dissolve the tri-phosphate, and to the clear 
solution diluted with water, if necessary, I 
add bone-ash, animal charcoal, precipitated 
tri-phosphate, or finely-ground mineral phos- 
phate (preferring the bone-ash, animal char- 
coal, or precipitated tri-phosphate) in such 
quantity, that the tri-phosphate added is 
equal to that in the solution, and then I pro- 
ceed to mix and wash as in the previous case. 
This second process is, as will be seen, a 
simple modification of the process first de- 
scribed, and the instructions given in respect 
thereto will, for the most part, be applicable 
to the second process, and are sufficient for 
the carrying the said process into practical 
effect. 

"3. I treat substances containing tri-phos- 
phate of lime with sulphuric acid in the same 
manner as in making ordinary super-phos- 
phate of lime, and I dissolve out in a small 
quantity of water the soluble acid mono- 
phosphate produced ; to this solution I add 
bone-ash, animal charcoal, precipitated tri- 
phosphate, or any mineral phosphate, in fine 



254 PURE FERTILIZERS. 

powder (preferring the bone-ash, animal char- 
coal, or precipitated tri-phosphate) in such 
quantity, that the tri-phosphate added is 
equal to that in the solution. I mix these 
materials as in the previous case ; but, as the 
mixture does not contain any chloride of cal- 
cium, it does not require washing ; but after 
standing in the moist state for a sufficient 
time to allow of the production of the di- 
phosphate (and, as is ascertained by testing, 
as already explained in respect to the first 
process) it is dried, if necessary, at a tem- 
perature of 240"^ or 250"^ Fahrenheit for use. 
In some cases I prefer to treat the phosphate 
of lime in the first part of this process with 
sufficient sulphuric acid to combine with the 
whole of the lime and to liberate phosphoric 
acid. In this case I add to the solution of 
this acid as much bone-ash, or other sub- 
stance as contains twice the phosphoric acid 
contained in the solution. In making use of 
the method 3, the solution of acid phosphate 
or of phosphoric acid produced by the action 
of sulphuric acid on phosphate of lime may, 
if necessary, be concentrated by evaporation 
before mixture with the bone-ash or other 
material. The quantity of this solution used 
should be sufficient to act upon the carbonate 
as well as the phosphate of lime of the bone- 



DI-PHOSPHATE OF LIME. 255 



animal charcoal, or other phosphate ; the 
heat employed in this case may be as high as 
350'' without injury. 

" 4. I evaporate a solution of tri-phosphate 
of lime in hydrochloric acid, and heat the 
residue to such temperature as shall be suffi- 
cient to enable the mono-phosphate of lime to 
react upon one equivalent of the chloride of 
calcium present and condensing the hydro- 
chloric acid vapours given off, I may digest 
the residue with chalk or other form of car- 
bonate of lime to decompose any mono-phos- 
phate of lime which may remain, and I wash 
the di-phosphate produced to free it from chlo- 
ride of calcium, taking care to precipitate from 
the wash-water by lime any phosphoric acid it 
may contain. In carrying out this process, I 
dissolve the crude phosphate of lime in hy- 
drochloric acid diluted with the smallest pos- 
sible quantity of water, so as to avoid un- 
necessary evaporation. I dry down the solu- 
tion in pans or ordinary evaporating furnaces, 
taking care to arrange for the collection and 
condensation of the acid fumes which will be 
driven off ; the heat should not exceed 350° 
Fahrenheit ; otherwise, tri-phosphate of lime 
may be produced. The materials should be 
frequently stirred ; and, in order to complete 
the decomposition, the dry products, after re- 



256 PURE FERTILIZERS. 

moval from the furnaces, may be powdered, 
mixed, and again heated. I wash the di- 
phosphate with or without addition of chalk, 
according to the amount of acid phosphate 
undecomposed, and dry the di-phosphate as 
in the previous processes. I precipitate any 
phosphate in the wash-water with caustic 
lime. 

" 5. I find, that when a solution of phos- 
phate of lime in hydrochloric acid is precipi- 
tated by milk of lime or lime water, as is 
well known, a small part of this precipitate 
may be produced in the state of di-phosphate, 
and special precautions will be necessary, as 
hereinafter described, to prevent the greater 
part being produced in the state of ordinary 
tri-phosphate of lime. When preparing the 
di-phosphate of lime in this manner, I add 
the lime very gradually, and stop short in the 
addition of lime some time before the liquid 
becomes alkaline ; that is to say, whilst the 
mixture is still strongly acid with the acid 
mono-phosphate of lime and remains so. 
After continued stirring I run off the liquor, 
and, having washed away the chloride of cal- 
cium, I dry the residue, which is the di-phos- 
phate. I am careful to add t6 the liquor 
which is run off, and to the water with which 
I wash away the chloride of calcium from the 



DI-PHOSPHATE OF LIME. 257 

di-phosphatc, sufficient lime to precipitate any 
phosphate it may contain before discharging 
it to waste ; or, I add, in the first instance, 
sufficient lime to render the liquid alkaline. 
And, to precipitate all the phosphate of lime, 
I run off the liquid, and digest the precipitate 
in a fresh and strong solution of phosphate 
of lime in hydrochloric acid, or in a solution 
of acid phosphate or mono-phosphate of lime, 
by which the whole or greater part is con- 
verted into di-phosphate of lime, which I 
wash and dry as before. 

"6. In order to precipitate the di-phosphate 
of lime free from tri-phosphate of lime from 
a solution of phosphate of lime in hydrochloric 
acid, I use carbonate of lime in the form of 
chalk limestone, magnesian limestone, or mar- 
ble, which I digest with the solution ; I find 
that, in this case, no tri-phosphate of lime is 
produced. If an excess of chalk or other car- 
bonate of lime has been employed, I get rid 
of this by digesting the di-phosphate in a 
further quantity of the phosphate solution. 

'* In carrying out the method I use any 
ordinary vessel or tank, and I prefer to 
employ chalk in very fine powder as a preci- 
pitant. I agitate the solution of phosphate 
in hydrochloric acid with the chalk in vats 
furnished with revolving];- arms or beaters, as 



258 PURE FERTILIZERS. 

is well known, till such time as I find by 
examination of the liquid that the greater 
part of the phosphate is precipitated as di- 
phosphate, which I then wash and dry ; or I 
mix the solution of phosphate with chalk in 
a pug-mill, and leave the mixture at rest till 
the decomposition is complete, when I wash 
out the chloride of calcium by cold water. If 
the hydrochloric acid has been fully neu- 
tralized by phosphate of lime, the quantity of 
chalk to be used will be about one-third that 
of the real phosphate of lime in the solu- 
tion. 

" It will be understood that in all cases 
when di-phosphate is washed to separate 
chloride of calcium, the wash-water should be 
precipitated with lime to avoid loss of phos- 
phate. I use the di-phosphate of lime pro- 
duced by either of the foregoing methods 
without further treatment, or after the addi- 
tion of a small quantity of sulphuric or other 
mineral acid as manure, and I also employ it 
in the manufacture of phosphorus. I find 
that the di-phosphate of lime is only soluble 
to a limited extent in cold water ; when the 
water is heated the di-phosphate is converted 
into mono-phosphate or acid phosphate, and 
tri-phosphate or insoluble phosphate, and I 
sometimes treat the di-phosphate in this 



DI-PHOSPHATE OF LIME. 259 

manner for the purposes of manure or for 
other practical uses." 



Delignys Process. 

This process, by Ernest Deligny, of Paris, 
refers to the production of sesqui-basic phos- 
phate of lime ; and I give the description of 
it in a translation of that chemist's own lan- 
i>"uag"e : — 

o o 

'' My process relates to the production of 
what may be termed sesqui-basic phosphate of 
lime, which product is obtained from bones, 
mineral phosphates, or other phosphatic 
sources, and which is soluble in water, or in 
water containing carbonic acid, and it con- 
sists, first, in submitting tri-basic phosphate 
of lime, either natural or artificially prepared, 
to the action of acid phosphate of lime, 
whereby a sesqui-basic phosphate of lime is 
obtained ; second, in submitting to the action 
of heat either that product, w^hich is obtained 
in effecting the decomposition of bones, co- 
prolites, or other phosphate of lime, by micans 
of hydrochloric acid, or a mixture of a solution 
of chloride of calcium and of acid phosphate 
of lime, whereby the chloride of calcium is in 
part decomposed, and a sesqui-basic phos- 

S 2 



26o PURE FERTILIZERS. 

phate of lime formed. The solid sesqui-basic 
phosphate of lime thus obtained is to be 
separated from the salts of lime contained in 
the supernatant solution, and after having 
been washed and dried may be employed for 
such purposes as the acid phosphate of lime 
is now used, or for other applications. 

"The reactions and operations indicated in 
the Specification of Letters Patent granted to 
Michael Henry as a communication from 
Ernest Deligny, and bearing date the Twenty- 
first of April, One thousand eight hundred 
and sixty-nine, No. 1224, are obtained in 
metallic vessels heated by an open fire, and 
the temperature may be raised considerably 
above 212" Fahrenheit by reason of the quan- 
tity of chloride of calcium contained in the 
liquids. 

"In practically carrying out these opera- 
tions, however, difficulties are encountered 
when a liquid is heated in which a precipitate 
is formed. This latter adheres to the sides of 
the boilers and exposes them to the risk of 
being burnt. This evil is so much the more 
serious that it becomes necessary to employ 
leaden boilers, iron being too easily attacked. 
I, therefore, propose to apply the heat by in- 
jecting steam into the liquid itself, which 
also allows of the employment of wooden 



DI-PIIOSPHATE OF LIME. 261 



vessels. It was, however, discovered that at 
the boiling temperature thus produced the re- 
actions were modified, and that whatever was 
the duration of the time of heating, the crys- 
tallized precipitate obtained remained in the 
state of sesqui-phosphate of lime, which may 
be represented by the formula, 2CaO, HO, 
PO5 X 3CaO, PO5 ; or a combination of an 
equivalent of bi-basic phosphate, with an 
equivalent of tri-basic phosphate, which re- 
tains up to 260° Fahrenheit an equivalent of 
water of combination. 

'' This novel product is obtained in the 
form of a fine white brilliant crystalline pow- 
der of great density, which is rapidly precipi- 
tated from the liquid in which it is produced. 
It is washed with the greatest facility, and is, 
by that means, completely freed from the chlo- 
ride of calcium, and it may be easily drained 
and dried. The resulting product is soluble 
in water, or in water charged with carbonic 
acid. The preparation of this product is 
effected by attacking mineral phosphates of 
lime or bones with hydrochloric acid, and 
thus producing a concentrated solution of 
soluble acid, phosphate of lime, and chloride 
of calcium, and effecting the reaction by 
means of heat of the acid phosphate of lime 
upon chloride of calcium and the precipitation 



262 PURE FERTILIZERS. 

of the bi-basic phosphate of lime or of the 
tri-basic phosphate of lime, setting, thereby, 
free one half or the whole of the hydrochloric 
acid employed for dissolving the phosphates 
originally operated upon. The tri-basic phos- 
phate, upon being heated by means of a jet of 
steam with the acid phosphate, is converted 
into a sesqui-basic phosphate, and a crystal- 
line deposit is formed. The reaction is more 
easily produced if the acid phosphate be 
in excess ; or the sesqui-basic phosphate of 
lime may be produced by adding lime to a 
solution of the acid phosphate of lime, and 
thus producing tri-basic phosphate of lime, 
which by reason of the presence of the acid 
phosphate upon the application of heat con- 
verted into sesqui-basic phosphate of lime. 
Nearly the whole of the phosphoric acid con- 
tained in the liquid may be thus precipitated 
in the form of crystalline sesqui-basic phos- 
phate. It is advisable, however, not to preci- 
pitate the whole of the phosphoric acid, as, 
should iron be contained in the phosphates, 
it would be precipitated and would injure the 
purity of the product. As soon as the reaction 
is terminated, the supernatant liquid may be 
poured into a separate vessel and allowed to 
settle, and the liquid containing the chloride 
of calcium be separated (which may be applied 



DI-PHOSPHATE OF LIME. 263 



to any of its known uses). The precipitated 
phosphate is drained and washed, and finally 
dried either in the open air or in a stove, 
which is heated by utilizing waste heat." 

Chloro-Phosphate of Lime. 

This is a peculiar product, originated by 
J. Thomas Way, who claims for it the grade 
of a potential fertilizer. The subject has 
been studied with the great ability which cha- 
racterizes all the professional work of that 
chemist ; and it is due to both him and the 
reader, that I should give the description of 
the process in its author's own language, 
which is as follows: — 

'* Heretofore, it has been usual to employ 
in the manufacture of superphosphate of lime, 
oil of vitriol or sulphuric acid to render solu- 
ble the phosphate of lime, which it does by 
combining with a part of the lime forming 
gypsum, which is practically insoluble and 
remains without inconvenience in admixture 
with the soluble phosphate. It has not been 
practicable to use hydrochloric acid in place 
of sulphuric acid in this manner, because the 
mixture, if so made, would be deliquescent 
and unfit for the ordinary purposes of manure 



264 PURE FERTILIZERS. 



from its containing free or uncombined chlo- 
ride of calcium. 

** Now, this process consists of different 
methods of employing hydrochloric acid in 
conjunction with sulphuric acid in such man- 
ner, that an article of high quality and free 
from the objection above-named, is obtained 
more economically than by the use of sul- 
phuric acid alone. 

''The methods to be described depend upon 
the production of a compound of acid or 
mono-phosphate of lime with chloride of cal- 
cium in the proportion of one equivalent of 
each. This salt, which I call chloro-phos- 
phate of lime, was discovered by myself seve- 
ral years ago ; it is, practically, non-deli- 
quescent. 

*' If a phosphate of lime were met with in 
nature consisting of one equivalent of phos- 
phoric acid united with two equivalents of 
lime, it would suffice with such a phosphate 
to dissolve it in hydrochloric acici and evapo- 
rate to dryness to obtain the salt above- 
mentioned. During the evaporation the phos- 
phoric acid would decompose one half or one 
equivalent of the chloride of calcium present 
with the escape of an equivalent of hydro- 
chloric acid and the formation of mono-phos- 
phate of lime, which would unite A\ith the 



I 



T)I-PHOSPHATE OF LIME. 265 

rest of the chloride of calcium to form 
' chloro-phosphate of lime'. But it so hap- 
pens that ordinary phosphate of lime contains 
three equivalents of lime to one equivalent of 
phosphoric acid, and a solution of this when 
evaporated gives an equivalent of chloride of 
calcium in addition to that which can com- 
bine with acid phosphate of lime ; this addi- 
tional equivalent renders the product deli- 
quescent and practically unfit for manure. 

** Now, the object of the processes to be 
described is to adjust the balance between the 
lime and phosphoric acid, so as to reduce the 
chloride of calcium left in the product to one 
equivalent for each equivalent of phosphoric 
acid ; and it is manifest that this can be done 
by decreasing the quantity of lime or by in- 
creasing the proportion of phosphoric acid. 

" I shall shortly recapitulate the methods 
by which I accomplish this object. 

** I dissolve mineral phosphate of lime, 
burnt bones, or other substances consisting 
principally or largely of phosphate of lime, in 
hydrochloric acid of any convenient strength, 
preferring, however, a solution of this acid of 
sixteen degrees Twaddle or sixteen per cent, 
real acid. The solution of phosphate so 
made, which I shall call * the liquor', I deal 
with in one or other of the following ways : 



MOHh'IT on //i,M,iiitii;i,liiiT i.rl-rinln, 




Generator and Vats for Precipitation by Ahhonia. 



266 PURE FERTILIZERS. 

" And, in order to a more easy compre- 
hension of the subject, I will, in the first in- 
stance, suppose that the liquor contains phos- 
phoric acid and lime in the proportion of one 
equivalent or combining proportion of the 
former to three equivalents or combining pro- 
portions of the latter. Where carbonate of 
lime has existed in the mineral or other phos- 
phate of lime the proportion of lime will be 
greater than this ; but to this I will after- 
wards refer. 

'* The following are methods of reducing 
the proportion of lime so as to produce chloro- 
phosphate of lime as the product : 

*'A. Adding sulphuric acid to 'the liquor', 
separating by filtration the sulphate of lime 
produced, and evaporating to dryness. 

" B. Adding sulphuric acid as in A, and 
evaporating the whole to dryness without 
separation of the sulphate of lime. 

" C. Evaporating the liquor to dryness, 
mixing the product with sulphuric acid, and 
drying up the mixture by heat. 

" The product in A is ' chloro-phosphate of 
lime', with some insoluble phosphate produced 
in the evaporation. 

*Tn B and C the chloro-phosphate is mixed 
with sulphate of lime. 

" D. Evaporating the liquor till crystals of 



DI-PHOSPHATE OF LIME. 267 

chloro-phosphate form, separating the crystals 
and adding to them sulphuric acid to decom- 
pose the adhering chloride of calcium, and 
drying up the mixture or dissolving the crys- 
tals and recrystallizing. 

"In all these processes sulphate of soda 
may be substituted for sulphuric acid, but at 
an increase of cost and a diminution in the 
quality of the product. 

" By all of the above methods a portion of 
the base is either rendered insoluble or re- 
moved. 

" The methods of increasing the quantity of 
phosphoric acid in lieu of diminishing the 
quantity of base consist in substituting for 
the sulphuric acid phosphoric acid or acid 
phosphate of lime in the processes above set 
forth ; the whole of the base is thus converted 
into chloro-phosphate. Without dissolving 
the phosphate of lime, in the first instance, in 
hydrochloric acid, I sometimes add to pow- 
dered phosphate of lime sulphuric and hy- 
drochloric acid in such proportions as to form 
sulphate of lime and chloro-phosphate of lime, 
and I dry up the products for use. 

" Having thus recapitulated the processes 
which form the subject of the present patent, 
and each of which may in particular circum- 
stances possess advantages, I proceed to dc- 



268 PURE FERTILIZERS. 

scribe more particularly the way in which 
they should be carried out. 

** Process A. — I take any convenient quan- 
tity of the ' liquor' prepared in the manner 
already described, and having ascertained by 
chemical analysis how much phosphoric acid 
and lime it contains, I add to it such quan- 
tity of oil of vitriol, ' brown acid', or other 
form of sulphuric acid, as shall be sufficient 
to unite with one-third of the lime present 
in ' the liquor'. For instance, I take one 
hundred gallons of the liquor, and having 
found that this quantity contains seventy-one 
pounds of phosphoric acid and eighty-four 
pounds of lime (which are the chemical equi- 
valents in pounds in tri-phosphate of lime) I 
add forty-nine pounds (or one equivalent in 
pounds) of oil of vitriol, or a corresponding 
quantity of ' brown acid', this quantity being 
capable of uniting with twenty-eight pounds 
or one third of the lime present. I mix the 
sulphuric acid and the liquor by agitation, 
and by means of filtration through cloth or 
otherwise I separate the sulphate of lime, 
which has been produced by the addition of 
the sulphuric acid, which sulphate of lime I 
wash by successive quantities of water. The 
solution so obtained and the washings con- 
tain the phosphoric acid and two-thirds of 



DI-PIIOSPHATE OF LIME. 269 

the lime originally present in the liquor. I 
evaporate these liquids in a reverberatory 
furnace or other convenient arrangement to 
a thick paste, collecting and condensing the 
vapours of hydrochloric acid which are given 
off during the process, and I further dry it up 
by steam or other heat, avoiding a tempera- 
ture much above two hundred and twelve 
degrees Fahrenheit. 

" I would remark that whilst it is necessary 
that the quantity of sulphuric acid should not 
be less than that above inclicated,a larger quan- 
tity is not objectionable (except on the ground 
of unnecessary expense), provided that it 
does not exceed twice the above amount. 

"When the liquor, as is frequently the 
case, contains more than 84 parts of lime to 
71 parts of phosphoric acid, I use an addi- 
tional quantity of sulphuric acid, for such 
excess, in the proportion of 49 lbs. of oil of 
vitriol (or a corresponding quantity of ' brown 
acid' or other strength of sulphuric acid, for 
every such additional 28 lbs. present. For 
instance, supposing that in 100 gallons of 
liquor containing 71 lbs. of phosphoric acid I 
find 98 lbs. of lime instead of 84 lbs., then, in 
addition to 49 lbs. of oil of vitriol, as in the 
previous instance, I require to use 241 more 
to deal with the excess of 14 lbs. of lime pre- 
sent in the liquor. 



270 PURE FERTILIZERS. 

" Practically it is generally known without 
chemical analysis what the nature of the 
liquor is by that of the raw phosphate from 
which it was produced, and the sulphuric 
acid necessary may readily be calculated. 

" In the final evaporation or drying up of 
the product I prefer to keep the temperature 
as little above 212"^ Fahrenheit as may be. 
Nevertheless the product is not destroyed at 
a temperature of 280" or 300° Fahrenheit, but 
at such temperature a larger proportion of the 
soluble phosphate becomes insoluble. 

" Process B. — This method is carried out 
essentially as in the case of A, with the ex- 
ception that the sulphate of lime remains in 
the product, which is not therefore of such 
high quality as regards per-centage of soluble 
phosphate as in the other process. 

** Process C. — In this process I evaporate 
the liquor without addition of sulphuric acid, 
and the drying may with advantage be 
effected at a higher temperature than in A 
and B, namely, at 300° Fahrenheit, or even 
higher. With the dry product I mix sul- 
phuric acid by suitable mechanical means, 
subsequently heating the mixture to 2 12" or 
thereabouts to expel hydrochloric acid. The 
quantity of sulphuric acid to be used in this 
case can be calculated in the same way as 



DI-PHOSPHATE OF LIME. 271 

in processes A and B, the calculation being 
based on the quantity of liquor evaporated, or 
the dry residue may be examined for the pro- 
portion of phosphoric acid and lime con- 
tained in it, and the sulphuric acid calculated 
as in the other cases. 

" D. — This process somewhat differs from 
that before described, inasmuch as the chloro- 
phosphate of lime is removed from the excess 
of chloride of calcium in great part by crystal- 
lization instead of the excess of chloride of 
calcium being separated from the chloro- 
phosphate entirely by chemical agency. I 
evaporate ' the liquor till it begins to show 
signs of crystallization. I allow it to cool, 
and I separate the crystals from the mother- 
liquor by drainage and pressure. 

*' I ascertain the quantity of chloride of 
calcium present in the crystals over and above 
the proper quantity to form chloro-phosphate, 
and I add an equivalent of sulphuric acid, or 
acid phosphate of lime, or half an equivalent 
of phosphoric acid for each equivalent of 
chloride of calcium in excess, and dry up the 
product at 212° Fahrenheit, or thereabouts, 
or I add the sulphuric acid in any additional 
quantity up to such quantity as is sufficient 
to decompose the whole chloride of calcium 
present, driving off the hydrochloric acid by 



272 PVRE FERTILIZERS. 

heat, but in this case the product is no longer 
chloro-phosphate of lime, but a mixture of 
acid phosphate of lime and sulphate of lime, 
similar to that made by decomposing di- 
phosphate of lime by sulphuric acid. 

** In dealing with the licjuor for crystalliza- 
tion, as now described, I sometimes add be- 
fore evaporation lime or chalk to neutralize 
free acid, by which the liberation of hydro- 
chloric acid fumes is avoided. The chalk or 
lime is added so long as it dissolves in the 
liquor. 

" When dealing with the liquor by increas- 
ing the proportion of phosphoric acid in re- 
lation to the lime, I obtain the acid phosphate 
of lime for the purpose from ordinary super- 
phosphate of lime, made by the action of sul- 
phuric acid on phosphate of lime. The phos- 
phoric acid is obtained by using an additional 
equivalent of sulphuric acid in excess of that 
employed in the manufacture of superphos- 
phate of lime. 

" I will give an example. I take lOO 
gallons of liquor, in which I will suppose, as 
before, that the relation of the lime to the phos- 
phoric acid is as three to one in equivalents, 
and that the lOO gallons contain 71 lbs. of 
phosphoric acid and 84 lbs. of lime. To this 
I add so much of acid phosphate of lime as 



DI-rilOSPlIATE OF LIME. 273 



will contain 71 lbs. or an equivalent in pounds 
of phosphoric acid, that being the quantity of 
phosphoric acid in the state of acid phosphate 
of lime which will combine with the equiva- 
lent of chloride, of calcium in excess, or I add 
so much of a solution of phosphoric acid as 
will contain 35^ lbs., or half an equivalent in 
pounds of phosphoric acid, that being the 
quantity of uncombined phosphoric acid which 
will convert the chloride of calcium into chloro- 
phosphate. I evaporate the solution to dry- 
ness, as before. The product being, practi- 
cally, chloro-phosphate of lime, if the liquor 
contains an excess of lime beyond the three 
equivalents, I increase the quantity of acid 
phosphate or of phosphoric acid accordingl}^, 
in the manner described, in using sulphuric 
acid. Instead of using solutions of phospho- 
ric acid or acid phosphate, I sometimes em- 
ploy the superphosphate itself, and mix it 
directly with the liquor, but in that case the 
product is of lower quality. 

"It is also evident that the two processes 
of reducing the proportion of lime by sul- 
phuric acid, etc., or increasing the proportion 
of phosphoric acid by its addition or that of 
acid phosphate of lime, may be practised con- 
jointly, if any advantage is derivable from 
such a plan. 



274 PURE PER TIL IZER S. 

"When I treat the raw insoluble phosphate 
without, in the first instance, preparing a 
liquor by dissolving it in hydrochloric acid, I 
proceed as follows : I take powdered mineral 
or other phosphate, and, having ascertained 
the proportion of tri-phosphate of lime and of 
carbonate of lime in it, I calculate, first, what 
quantity of sulphuric acid is necessary to de- 
compose the carbonate of lime, and what 
quantity will be required to unite with one 
out of every three parts of the lime present as 
phosphate. I also calculate how much hydro- 
chloric acid is necessary to unite with an 
equal quantity of lime. For instance, if the 
raw phosphate to be used contains 70 per 
cent, of tri-phosphate of lime and 10 per cent, 
of carbonate of lime, 221 lbs. will contain 
71 lbs. or one equivalent in pounds of phos- 
phoric acid and 22' i lbs. of carbonate of lime. 
For this quantity of carbonate of lime I shall 
require 217 lbs. of oil of vitriol, and for a 
third part or one equivalent of the lime 49 lbs. 
of oil of vitriol, or in all about 71 lbs., whilst 
of hydrochloric acid of 30^ Twaddle or 30 per 
cent. I shall require 119 lbs. ; that being the 
quantity of acid of this strength which con- 
tains one equivalent in pounds or 36 lbs. of 
real hydrochloric acid. 

" I mix the raw phosphate with the acids 



DI-PHOSPHATE OF LIME, 275 

by any convenient mechanical arrangement, 
and allow the mixture to lie for a time for 
completion of the chemical action, if neces- 
sary. I finally dry the product on hot floors 
or otherwise, at a heat not much exceeding 
212° Fahrenheit. From this product, which 
is a mixture of chloro-phosphate of lime with 
sulphate of lime and the impurities of the 
raw phosphate, I may obtain the chloro-phos- 
phate by treatment with water and evapora- 
tion of the solution. 

" In the foregoing description I have pro- 
vided for the giving off of hydrochloric va- 
pours during evaporation of the liquors ; this 
acid would be condensed in the usual way 
practised in alkali works. But by a modifi- 
cation of the process such production of hy- 
drochloric acid can be avoided when desirable. 
When mineral phosphate of lime is dissolved 
in hydrochloric acid, the liquor is usually a 
mixture of free phosphoric acid with chloride 
of calcium, but prolonged contact with the 
phosphate causes this phosphoric acid to pass 
into the state of acid phosphate of lime by 
solution of a further quantity of phosphate of 
lime, and in this state the liquor will consist 
of one equivalent of acid phosphate of lime 
mixed with two equivalents of chloride of 
calcium. If to this liquor acid phosphate of 

T 2 



276 PURE FERTILIZERS. 

lime from ordinary superphosphate of lime (or 
the superphosphate itself) is added in proper 
quantity (that is to say, one equivalent for 
each equivalent of chloride of calcium in ex- 
cess), and the liquor evaporated, chloro-phos- 
phate of lime will be produced without the 
formation or escape of hydrochloric acid. 
The same result will be obtained if to a liquor 
of the composition described sulphate of soda 
is added, and the sulphate of lime produced 
may either be separated before evaporation or 
may form part of the final product. The 
chloro-phosphate of lime, manufactured as 
above described, is valuable for use as manure 
either alone or mixed with other substances, 
or it may be used in the arts as a source of 
phosphoric acid. 

" I would have it understood that I claim 
the manufacture of soluble phosphate of lime 
in the state of chloro-phosphate (either for 
use as such, or for further treatment) by act- 
ing on the insoluble or natural phosphate with 
hydrochloric acid, preventing the preponder- 
ance of chloride of calcium by converting a 
portion of the base into sulphate or by the 
addition of a further quantity of phosphoric 
acid or acid phosphate of lime." 



CHAPTER XL 



THE MOTHER- LIQUOR OR WASH, AND THE 
MODE OF RECLAIMING ITS MATERIALS. 

In all of the preceding processes for obtain- 
ing the phosphate of lime by precipitation 
from its solution in hydrochloric acid, the 
mother-water is either wholly or partly an 
aqueous liquor of chloride of calcium. The 
almost invariable presence of carbonate or 
organate of lime in crude phosphate of lime 
makes this an absolute case, whether the pre- 
cipitant may be lime, carbonate of lime, am- 
monia, iron or aluminium oxide or phos- 
phate. 

Puye Chloride of Calcium. 

In the preparation of the phosphate of lime 
by ammonia, as described in Chapter viii, 
the preliminary treatment, with a limited 
portion of hydrochloric acid, is to restrict the 



278 PURE FERTILIZERS. 

action of the latter to the carbonate and or- 
ganate of lime constituents of the crude 
phosphate. The liquor thus formed, how- 
ever, will contain also some little of phos- 
phate of lime, together with larger or smaller 
traces of alumina and oxide of iron, if the 
acid and the heat of digestion are strong. 
This trace of phosphate having been re- 
claimed by precipitating with milk of lime, 
which also frees the liquor of alumina and 
oxide of iron, the mother-liquor is then a 
pure aqueous solution of chloride of calcium. 
It is only necessary, therefore, to evaporate 
the liquor to dryness, or to such a dense state 
that it will solidify on cooling, in order to 
convert it into a saleable commercial article. 
It is generally packed in sheet-iron barrels 
or drums, holding each about four hundred 
weight. Owing to its pure state, it is well 
adapted for the manufacture of artificial stone 
by Ransome's process. 

Again, in the processes of Chapters ix and 
X, for making the Colombian and di-phos- 
phates of lime, the final mother-liquor is 
wholly an aqueous solution of chloride of 
calcium in a state of purity, and only re- 



THE MOTHER-LIQUOR OR WASH. 279 



quires to be solidified by evaporation, in 
order to become a saleable and profitable 
article of commerce. 

Being thus made largely and as a by- 
product, it can be sold at a price which will 
render it independent of all competition. 

I have now in progress, with the co-opera- 
tion of Dr. B. W. Gerland, a course of practi- 
cal experiments for reclaiming the hydrochlo- 
ric acid by the concurrent action of a stream 
of sulphurous acid and blasts of steam and 
air in the chloride of calcium mother-liquor. 
This should form sulphate of lime and set 
free the hydrochloric acid, to be used over 
and over again an indefinite number of times 
for digesting the raw mineral, and thus 
adapt the process to those remote regions, 
inaccessible to acids, which contain deposits 
of mineral phosphate, pyrites, and sulphuret- 
ted ores. In the roasting of the latter, sul- 
phurous acid would be generated abundantly, 
so that a manufactory of refined phosphates 
could be thus established upon a single in- 
augural batch of hydrochloric acid. 

When the mother-liquor is chiefly a solu- 
tion of iron and aluminium compounds, it is 



28o PURE FERTILIZERS. 

probable that it might be made to give up its 
hydrochloric acid, in a free state, by the 
action alone of superheated steam. 



Sulphate of Animofiia as the Economiser. 

As a certain amount of ammoniacal salt 
will be required for the composition of special 
fertilizers, a portion of the wash-liquor may 
be used advantageously for converting sul- 
phate of ammonia into chloride of ammo- 
nium, the latter being preferable in that con- 
nection. Not only is there a small money 
profit by the transformation, but a gain of 
bulk, for the equivalent relation of the base 
ammonia in the chloride is much higher than 
in the sulphate ; and much less of the weight 
of the former will correspond in nitrogen 
value with a much larger weight of the 
latter. 

For this purpose, the wash-liquor is to be 
run into a clean wooden vat, constructed as 
described at p. 127, and shown by Plate 11. 
Having been brought to 212^ Fahrenheit, a 
dense aqueous solution of sulphate of ammo- 
nia is then to be poured in during constant 



THE MOTHER-LIQUOR OR WASH. 



2ai 



ag-itation and heating by the currents of 
steam. 

A double exchange of bases takes place, 
white hydrated sulphate of lime precipitates, 
and chloride of ammonium forms in solution. 

Repose being allowed, the solution rises to 
the top as supernatant liquor, and then is to 
be drawn off clear, through the cocks, into the 
evaporating pans (Plate 13). To the deposit 
is now to be added some fresh w^ater from 
the hydrant, and the whole boiled and allowed 
to settle as before. The clear wash-water is 
to be drawn off into the evaporating pan as 
was the strong liquor just previously. This 
washing is to be repeated with a second relay 
of fresh water in the same manner. The de- 
posit is then wholly or nearly free of all am- 
monium salt and is to be run off into large 
shallow troughs placed under an open shed, 
where it is left to dry spontaneously. When 
dried, it will be a valuable substitute for 
ground plaster in agriculture. A portion of 
it will be needed for drying the bi-phosphate 
of lime, as explained in a subsequent chapter. 

In the meantime, the liquor and its two 
wash-waters in the evaporating pan must be 



282 PURE FERTILIZERS. 

undergoing concentration by heat to a dense 
solution. When it reaches the crystallizing 
point, the heat is to be stopped. 

On cooling, it will form a solid saline cake 
of chloride of ammonium, which can be 
broken up and packed in barrels for market. 

The expense of a separate vat for making 
the aqueous solution of alkaline sulphate 
may be saved by putting the requisite quan- 
tity of ammonium sulphate in the precipi- 
tating vat, and dissolving it there previously 
to the entrance of the wash-liqiwr. Then, 
by stirring as the wash-liquor enters, the de- 
composition will take place, as has just been 
explained. The currents of steam from the 
heating-pipes produce the necessary agitation 
and intermixture. 

Sulphate of potassa may be used in a simi- 
lar manner to re-place the ammonium sul- 
phate whenever it is desired to produce chlo- 
ride of potassium. 

I distinguish by the name of economisers 
those agents which are employed to reclaim 
the wash-liquor, because they convert the 
latter into valuable products by saving the 
cost of the hydrochloric acid and improving, 



THE MOTHER-LIQUOR OR IV A SIT 283 

otherwise, the general advantages of the fer- 
tilizer. 

If sulphate of ammonia is the economiser, 
the necessary proportion of it is i -32 pounds 
for every per cent, or pound of carbonate of 
lime in the original raw mineral. This will 
produce I'oj pounds of chloride of ammo- 
nium and 172 pounds of hydrated sulphate 
of lime. In other words, every pound of sul- 
phate of ammonia will react upon the wash- 
liquor to produce o'8o pound of chloride of 
ammonium and i '30 pounds of hydrated sul- 
phate of lime. 

Sulphate of Pot ass a as the Economiser. 

If sulphate of potassa should be used as 
the economiser, the proportion required is 
174 pounds for each per cent, or pound of 
carbonate of lime in the original raw mineral. 
The products from these ratios will be i'49 
of chloride of potassium and 1 72 of hydrated 
sulphate of lime. That is, every pound of 
sulphate of potassa employed in decomposing 
the wash-liquor of chloride of calcium will 
yield o"856 lb. of chloride of potassium and 
0-988 lb. of hydrated sulphate of lime. 



284 PURE FERTILIZERS. 

A Mixture of Sulphates of AmmoHia and 
Potassa as the Economiser. 

A mixture of potassa and ammonia sul- 
phates may be apportioned from those data 
when it is desired to produce the mixture of 
those bases. To this end, one pound of sul- 
phate of potassa is equivalent to 0758 pound 
of sulphate of ammonia. On the other hand, 
one pound of sulphate of ammonia corre- 
sponds with 1*32 pounds of sulphate of po- 
tassa. 

When the decomposition of the wash is to 
be made by a mixture of these sulphates, the 
manipulations are the same as has been ex- 
plained for them severally. 

Crude Ammonia Liquor as the Economiser. 

The economiser may be crude ammonia 
liquor in place of sulphate of ammonia ; but 
then the lime is precipitated as carbonate 
with some little sulphate. The ammonia 
product, however, will be chloride, and in 
slightly greater quantity than from sulphate 
of ammonia as the economiser. This slight 
excess arises from the fact that gas-liquor 



THE MOTHER-LIQUOR OR WASH. 285 



contains some chloride and other salts than 
the carbonate, which does the precipitation. 
These not being affected by the chemical 
action in the vat, evaporate to crystalline 
mass with the newly-formed chloride, when 
the liquor is put into the concentrating pan. 

The quantity required for decomposing 
the chloride of calcium or ivash-liquor will 
depend upon the strength of the gas-liquor. 
Assuming that it contains the usual average 
of o"47 per cent, of dry ammonia gas, then, 
for every hundred pounds of hydrochloric 
acid of specific gravity riy contained in 
the wash-liquor, there will be needed six 
hundred pounds of gas or crude ammonia 
liquor, with about twenty-five pounds addi- 
tional for contingencies. 

Owing to the presence of sulphate of am- 
monia, invariably, in the gas-liquor, the car- 
bonate of lime precipitate will ahvays contain 
more or less of sulphate of lime. The quan- 
tity of this precipitate cannot be precisely 
stated, on account of the variability in the 
composition of gas-liquor. If there is any 
iron present as impurity, it will give a 
greyish-blue colour to the precipitate, be- 




Details of the Precipitation Vat & Ammonia Generator 



Tnllma* CV,6(j.Palf'il..N 



i=:^r;r^:'::.c tm. 



286 PURE FERTILIZERS. 

cause of the formation of sulphuret of iron 
with the sulphur of the gas liquor. 

Precautions must be observed to protect 
the workmen against the evolution of in- 
jurious sulphuretted vapour when gas-liquor 
is used. This is done by adding some chlo- 
ride of iron to the wash-liquor, in order to 
precipitate the sulphuret, avoiding the use of 
steam, and substituting mechanical stirring. 

In this case, small samples of the liquor 
must be drawn from the vat through try- 
cocks, and tested from time to time, to deter- 
mine when enough of gas-liquor has been 
added. This will be known when a further 
addition ceases to throw down a precipitate. 

The great profit afforded by the use of gas- 
liquor as the economiser renders it expedient 
to prefer that material to all the others, when 
a necessary supply can be obtained conve- 
niently. 

The abundant supply of chloride of cal- 
cium, as a cheap by-product in these pro- 
cesses, affords a convenient and profitable 
means of reclaiming from waste, as ammonia 
salt, the liquor of all of those gas-works 
which arc now inaccessible to sulphuric or 



THE MOTHER-LIQUOR OR WASH 287 

hydrochloric acids. Being solid and heavy, 
it is indeed a most advantageous substitute 
for the latter in this connection, not only on 
account of its better transportation condi- 
tions, but for other good practical reasons. 

This "mother-liquor" may be utilized, also, 
by passing through it concurrent streams of 
gaseous ammonia and carbonic acid. Car- 
bonate of lime precipitates, and chloride of 
ammonium rests above as a clear liquor, to be 
evaporated to crystals or dryness for market. 

The precipitate, on being pressed and cal- 
cined, will give quick-lime, and at the same 
time reproduce its carbonic acid for subse- 
quent operations. 

Phosphate of Soda as the Econoniiser. 

Townsend's method of converting Redonda 
Guano into phosphate of soda (Chapter 20) 
gives a most advantageous liquor for convert- 
ing this " mother-liquor" into pure phosphate 
of lime and table-salt. By mere intermixture 
of the two liquors, the phosphate of lime pre- 
cipitates, and chloride of sodium remains in 
solution, to be drawn off and evaporated to 
dryness for market. 



CHAPTER XII, 



ON THE PRINCIPLES OF THE SUPER- 
PHOSPHATING PROCESSES. 

In the manufacture of " commercial super- 
phosphate" by the direct action of sulphuric 
acid upon crude phosphate of lime, it is ex- 
pedient to select that kind of the latter mate- 
rial which is most free from carbonate of 
lime, fluoride of calcium, iron and aluminium 
compounds, and sand or silica. 

The reasons are obvious ; for, phosphate of 
lime being the only constituent required, all 
of its usual associates are foreign to the pro- 
cess of conversion. Thus sand is a valueless 
component, and would dilute the product 
disadvantageously. Carbonate and organate 
of lime, oxides of iron and aluminium, are 
not only diluents of the product, but they in- 
vest it with a permanent tendency to damp- 
ness. Moreover, they waste both time and 



SUPERPIIOSPHATING PROCESSES. 289 

acid ; being, in fact, barriers to the action of 
the sulphuric acid upon the tri-phosphate of 
lime constituent, for this last remains intact 
until they have been overcome chemically. 
I term them, therefore, profligate elements or 
associates. 

The decomposition of tri-phosphate of lime 
into bi-phosphate has been explained already 
in full, and by diagram at p. 73, Chapter in. 
It has been there shown, that a very large 
proportion of hydrated sulphate of lime is 
the inevitable accompaniment of the chemi- 
cal treatment of the first for conversion into 
superphosphate. So much is this sulphate 
in excess of the bi-phosphate, that even 
though the tri-phosphate under operation 
might be absolutely pure, it would not be 
possible to make it yield a product of better 
bi-phosphate strength than the following 
composition per cent. : — 

(i) Bi-phosphate of lime (CaO, 2 HO, POj) - 40-69 

Hydrated sulphate of lime (CaO, SO3, 2HO) - 59-31 



loo-oo 



But in Nature, the instances of a pure 

u 



290 PURE FERTILIZERS. 

phosphate of lime are very rare, and on such 
a small scale, that they suffice only as cabi- 
net specimens. The highest grades known 
are the phosphorite of Spain and certain 
apatites of Canada. These contain as much 
as ninety per cent, of phosphate of lime, 
when selected or so screened that the richer 
masses may be separated from the poorer. 
This culling operation shows, however, that 
the inferior parts form so nearly the whole 
amount of the mineral as to render those 
sources, of a very rich material for super- 
phosphating purposes, very narrow indeed. 
They could not be depended upon for a 
supply of any greater uniform average rich- 
ness than seventy per cent., even were they 
conveniently situated for mining and trans- 
porting the product. 

Of all the raw stocks available for the 
manufacture of superphosphate, bone-ash is 
the most advantageous. This contains, on 
an average, seventy per cent, of tri-phosphate 
of lime, ten per cent, of carbonate of lime, 
and twenty per cent, of other, profligate con- 
stituents. The supply, though considerable, 
is very largely inadequate. Moreover, it 



SUPERPIIOSPHATING PROCESSES. 291 



may bo applied directly to the soil without 
any preliminary treatment, as it is sufficiently 
active in its natural state for enriching the 
soil, and thus commands a price quite too 
high for this manufacture. 

Under the circumstances, then, which I 
have noted, the main reliance of the manu- 
facturer of superphosphate for his raw basis 
material is, and must continue to be, copro- 
lites, marlstones, and the so-called " Rock 
Guanos". 

The regular and abundant supply of these 
materials is no unimportant consideration in 
their favour. But, as the best do not average 
uniformly more than 60 to 65 per cent, of 
phosphate of lime constituents, and may fall 
as low as 40 per cent, in that element, it 
follows naturally that even under the first 
conditions there is a large ratio of profligate 
elements to dilute and deteriorate the super- 
phosphate product. 

For similar reason, the lower grades yield 
a product in which the superphosphate holds 
the low^est quantitative rank of all the com- 
ponents. These remarks refer to the usual 
methods of superphosphating, by mixing the 

u 2 



292 PURE FERTILIZERS. 



powdered mineral phosphate of lime with 
dilute oil of vitriol, allowing it to dry and 
then powdering it. 

Assuming that no earth, ground plaster, or 
other material has been added to promote the 
drying of the product, and also that bone-ash 
or the best available " Rock Guano" has 
been employed as the basis material, then, 
with the most careful manipulation, it is not 
possible to produce a " superphosphate" of 
greater percentage strength than is expressed 
by the following analytical table : — 

(2) Bi-phosphate of lime (CaO, 2HO, PO5) - 32-00 

Hydrated sulphate of lime (CaO, SO3, 2HO) - 5800 
Undesirable forei^^n matters - - 1000 



Total . , _ loooo 



Most generally, however, a more abundant 
material is employed, such as coprolites or 
marlstones, and these cannot be relied on for 
a higher uniform average of tri-phosphate of 
lime than 52 to 55 per cent. They contain, 
moreover, 12 to 15 per cent, of carbonate of 
lime. Hence, the product which represents 
the most of the superphosphate in the market 



SUPERPHOSPHATING PROCESSES. 293 

can have, at best, only the impoverished 
composition, per cent., shown by the follow- 
ing table : — 

(3) Bi-phosphate of lime (CaO, 2 HO, POJ - 26-50 

Hydrated sulphate of lime (CaO, SO3, 2 HO) - 54"5o 
Foreign and undesirable matters - - 1900 



1 0000 



I have assumed in these calculations that 
no excess of acid or water has been used to 
prevent the ''going back'' of the bi-phos- 
phate into an insoluble form or to add 
weight ; that no foreign matter has been 
mixed in to promote the drying of the pro- 
duct ; and that the manipulations have been 
skilful throughout, so as to assure a per- 
fect conversion of the whole of the tri-phos- 
phate element into soluble bi-phosphate. I 
have also excluded from consideration all 
fluoride of calcium, which is generally present 
in mineral phosphates of lime to an extent 
varying from one to ten per cent., and would 
reduce, consequently, the ratio of bi-phos- 
phate in the product by raising that of the 
sulphate. I do this to give to the usual pro- 



294 PURE FERTILIZERS. 



cess and its products the most favourable ex- 
position that is possible. Yet, with all these 
concessions, its defects show forth most 
glaringly to reproach the manufacturer and 
to awaken the suspicion of the farmer or 
planter. 

It rarely happens that a superphosphate 
reaches the planter in such a pure state. It 
is most generally degraded either through 
fradulent design or unscientific and careless 
manipulation, to such an extent that com- 
mercial samples seldom answer to a higher 
test than twenty per cent., and often fall as 
low as fifteen to ten per cent, of bi-phosphate. 

These figures refer to actual bi-phosphate 
(CaO, 2 HO, PO5), and not to their equivalent 
in tri-phosphate (sCaO, PO5). I make this 
explanation because it is the custom in the 
English market to offer and sell *' super- 
phosphate" upon this false expression of its 
real strength. When it is remembered that 
I '00 of tri-phosphate of lime represents only 
075 of soluble bi-phosphate, it becomes ap- 
parent, at once, that this deception is large 
in measure and unjustifiable. 

Evidence could not be more conclusive 



SUPERPHOSP HATING PROCESSES. 295 

than that which has been just noted against 
the defects of the methods in general use for 
making " superphosphate". It proves them 
to be alike discreditable to the manufacturer 
and unfair to his customers. Even supposing 
that the commercial product is always free 
from any designed or unintentional adultera- 
tion, and has uniformly the composition of 
the exemplar (3) on page 293, it is still an 
imposition, to a large extent, upon the credu- 
lity and confidence of the planter. 

Fertilizers are manufactured almost always 
in great commercial centres, and the custom- 
ers for them live often in distant parts not 
unfrequently remote from convenient chan- 
nels of transportation ; consequently the pack- 
age and freight charges upon a manure be- 
come important items for consideration. 

Sulphate of lime is a material common to 
every locality at trifling cost, and silica, sand, 
alumina, and oxide of iron are natural parts 
of every soil. Yet these form at least three- 
fourths of the " commercial superphosphate" 
in question ; and the purchaser of every 
hundred pounds is compelled to pay for the 
packing and transportation of all that larger 



296 PURE FERTILIZERS. 

worthless portion, in order to obtain the 20 
to 25 per cent, of valuable bi-phosphate. 

To remove these great defects and to im- 
prove the advantages of the " superphos- 
phate " to both producer and planter, I 
worked out upon a scientific basis the prac- 
tical methods, described minutely in Chap- 
ters XIII and XIV. 

In my earlier efforts towards the construc- 
tion of these processes, I cleared away first 
only the carbonate of lime from the raw 
rhineral by means of hydrochloric acid. This 
preliminary treatment, however, while it re- 
duced very materially the bulk and weight of 
the diluting influence, still left in the residue 
all of the sand, most of the organic matter, 
and much of the iron and aluminium com- 
pounds. Consequently, when sulphuric acid 
was added, subsequently, to convert the 
phosphate of lime constituent, it became not 
only more or less wasted, but caused a ten- 
dency to dampness in the resulting super- 
phosphate. 

Moreover, although the product was of 
very much higher quality than could be 
made from the mineral in its original crude 



SUP ERPHOSP HATING PROCESSES. 297 

state, it retained a large enough proportion 
of foreign matters to keep down its character 
to that of '' commercial superphosphate". 

These circumstances led then to the plan 
of treating the mineral phosphate with hy- 
drochloric acid and certain precipitants, so 
as to eliminate all the profligate elements. 

The cheap hydrochloric acid is made to do 
well the dirty work that is generally done 
badly by sulphuric acid ; and a pure tri- or 
di-phosphate of lime basis or " superphos- 
phate" is evolved by self-compensating means, 
from even inferior mineral ; so that all the 
subsequent operations of conversion are thus 
simplified and rendered economical to the 
utmost degree. 



CHAPTER XIII, 



ON THE MANUFACTURE OF PURE SUPER- 
PHOSPHATE" OF LIME. 

Thp: precipitated phosphates or the Colom- 
bian phosphate of Chapters vni, lx, and x, 
arc to be employed as the basis material. 
The use of either one of them simplifies the 
manipulation to the utmost, and reduces the 
expense of labour, time, and acid to the most 
economical degree. At the same time, the 
product is eminently superior both in quality 
and appearance. 

To convert it into *' superphosphate", it 
is only necessary to pass the well-washed 
precipitate through a mixing mill with the 
requisite proportion of sulphuric acid, and to 
lead the mixture into an enclosure where it 
may remain to ripen and dry. For this pur- 
pose, the precipitate in its wet pulpy state 
may be made to fall directly from the vat 



SUPERPHOSPHATE OF LIME. 299 



into the pug-mixer (Plate 21), by means of 
an inclined gutter or shoot, a stream of acid 
being arranged to enter at the same time into 
the hopper of the mill while the latter is in 
operation. The pulpy mass and acid are 
made thus to mingle thoroughly. 

The enclosures into which the mixture is 
received are simply vats of mason-work, as 
presented by Plate 24. When the mass has 
remained in these enclosures several days it 
will have set hard into pure " superphos- 
phate", which is a mixture of bi-phosphate 
and sulphate of lime, and contains, in this 
instance, more of the former than can be pro- 
duced from any other known material. 

Every ro of dry tri-phosphate of lime re- 
quires o'8i of brown oil of vitriol for its con- 
version into, soluble bi-phosphate. No re- 
gard need be paid to the small amount of 
di-phosphate which is present in the pulp ; 
for, although this requires less acid than the 
tri-phosphate, there are always some iron and 
alumina associates to make a compensation- 
balance in this connection. 

When the "superphosphate" has become 
dry it is to be shovelled out, dashed to 



30D PURE FERTILIZERS. 

granular powder by means of one of Carr's 
Disintegrators, and packed in bags for 
market. 

The pure state of this pulpy phosphate, 
and its loose texture, manifest their great 
advantage throughout this treatment. 

The composition of the product will be 
approximately as follows per cent. : — 

Soluble bi-phosphate of lime - - 39'00 

Hydrated sulphate of lime - - SS'OO 

Water - - - - roo 

Sand and silica - - - "50 

Iron and aluminium oxides and phosphates - 4*50 



1 00*00 



Its content of soluble bi-phosphate is equi- 
valent to 5 roo of pure tri-phosphate of 
lime. 

If the phosphate basis has been precipi- 
tated with due care, it will be free from iron 
and aluminium compounds and produce an 
equally pure superphosphate. Indeed, the 
di-phosphate, as made by my processes, can 
only contain those impurities by accident ; 
and, for that reason, and because it re- 
quires only half of the usual quantity of 



SUPERPHOSPHATE OF LIME. 301 



oil of vitriol for its conversion, it is a prime 
basis-material for " superphosphate", in every 
sense. 

Assuming that the di-phosphate of lime is 
pure and de-hydrated, then every 100 lbs. 
will require 50 lbs. of brown oil of vitriol, 
with some water of dilution ; and form 160 
lbs. of pure "superphosphate", having the 
following composition, approximately, per 
cent. : — 

Soluble bi-phosphate of lime (CaO, 2HO, PO^) 57'00 

Hydrated sulphate of lime (CaO, SO3 2HO) - 41 00 

Water, accidental . _ _ i-oo 

Sand and silica _ . . i-qo 

Iron and aluminium oxides and phosphates - traces 



1 0000 



The manipulations are the same as have 
just been described, and the product, which 
is white, sets and dries very promptly. Its 
content of soluble bi-phosphate is equiva- 
lent to 75 per cent, of pure tri-phosphate of 
lime. 

Owing to the concentrated nature of di- 
phosphate of lime and its great, potentiality 
as a fertilizer, it is eminentl}^ suitable for 



?o2 PURE FERTILIZERS. 



direct application to the soil ; and I have 
mentioned it as a basis-material for pure 
superphosphate, rather as an item of instruc- 
tion than with a view to recommend its use 
in that connection. It is almost too valuable 
for that purpose. 



CHAPTER XIV. 



ON THE MANUFACTURE OF PURE AND WHOLLY 
SOLUBLE BI-PHOSPHATE OF LIME. 

The basis-material for this product is either 
the precipitated or Colombian phosphate of 
Chapters vni, ix, and x. It is to be taken in 
its wet pulpy state, after a good washing, 
directly from the precipitation vat, and led 
through a shoot to a broad box at the bottom 
of the elevator (Plates 5, 6, and 7), instead of 
into the pug-mixer (Plate 21), as was just pre- 
viously directed for the manufacture of pure 
** superphosphate". 

In this instance, also, a weaker acid than 
the brown oil of vitriol may be used, as the 
resulting superphosphate need not be dry for 
the subsequent operation. Indeed, a certain 
amount of fluidity is even desirable. The 
chamber acid of i'45o will answer. This 
contains, in one hundred parts by weight, 



304 PURE FERTILIZERS. 



57*o oil of vitriol (SO3, HO) of specific 
gravity r845, or 46"48 (SO^) of dry sulphuric 
acid. The use of this weak acid will be a 
great economy when the manure factory has 
a sulphuric acid work annexed, for all the 
expense of concentrating it by evaporation to 
commercial strength for exportation is thus 
saved. 

The sulphuric acid is to be raised to the 
reservoir v (Plates 5 and 6), near the mixer b 
(Plates 5, 6, and 7), by means of the lift u. 
It may be delivered, also, to the mixer direct 
from a reservoir below, by means of a leaden 
pump, with the mouth of its delivery-tubes 
so adjusted as to let drop the acid in as 
gradual flow as may be required. 

Every pound of dry tri-phosphate of lime 
requires 51*28 pounds of dry sulphuric acid 
(SO3) for its decomposition, and this propor- 
tion is represented by rii pounds of the 
dilute acid of specific gravity r45o. 

The mass of pulpy phosphate having been 
brought by a gutter from the precipitation 
vat to the base of the elevator, is then to be 
carried up the belt and cups a a n n (Plates 
5 and 6) to the mixer. As the pulp falls into 



BI-PHOSPHATE OF LIME. 305 



the mixer a stream of acid should enter, so 
that the two may meet. Chemical action be- 
gins at once, and the decomposition of the 
phosphate goes on and becomes complete 
when the mass, after having fallen into the 
cylindrical vat (figs, i, 2, 3, 4, Plate 22) be- 
neath, is stirred and heated at short inter- 
vals, during ten or twelve hours. If the 
contents of the vat should tend to stiffen, they 
must be thinned by the addition of water, 
for a certain fluidity is necessary. Without 
it the motion of the stirrer would be difficult, 
and the decomposition of the tri-phosphate 
might not be thorough. 

The mass consists, now, of liquid bi-phos- 
phate of lime holding a little sulphate in 
aqueous solution, and a solid which is 
wholly hydrated sulphate of lime. 

By repose, the latter will settle with most 
of the former resting upon it as a clear 
supernatant liquor. This liquor is to be 
drawn off through the cocks of the vat, or by 
means of a syphon, into the basin portion of 
the kiln. 

However, as the mass retains yet a con- 
siderable portion of liquor, it must be washed 

X 



MORFIT on ihe ManiifatUuv orFenHhn 






\ 






Ground Line 



Details of Plant for Precipitation and Filtration. 



rfTiVhri^ r?i rfi fi^ rf^ fi^ flh ftl CB ill &i itl fTl itl ffl 



mil l mil I I I II I I I II III ill III III III 111 111 III iiimf 





Tniaial C^.60 httmoijr 



Speojlly deai^l fa KMiirfilfl Work ai 



306 PURE FERTILIZERS. 

by the addition of fresh water. The liquor, 
instead of being drawn off as before, is 
allowed this time to percolate downwards 
through the mass into the lower chamber of 
the vat. To facilitate this process of dis- 
placement, the lower chamber is to be ex- 
hausted of air by means of the air-pump, for 
which there is a coupling-screw y:onnection 
in the vat at 7ii. 

The vacuum thus produced in the lower 
chamber causes the liquor to filter through 
rapidly from above. The washing is to be 
repeated once or even twice. The mass is 
then clean and ready to be pushed out by the 
motion of the stirrers through the holes and 
shoots / /, and wheeled away for sale as a 
cheap substitute for ground plaster. 

The wash-waters are to be run into the 
basin part of the kiln with the previous 
strong liquor, and heated until a film of 
crystals begins to form. At this stage, there 
must be great care to moderate the fire ; for 
I have observed that the bi-phosphate of 
lime, when evaporated beyond the consistence 
of a wet crystalline mass, is apt to assume in 
part an allotropic condition which is com- 



BI-PHOSPHATE OF LIME. 307 

paratively insoluble. The heat must be 
stopped, therefore, when the liquor reaches 
the above-noted point. At this stage, also, 
it should receive its requisite proportion of 
drier. If, during the evaporation, there 
have been given off any white vapours of 
sulphuric acid, then the drier should be the 
Colombian phosphate, as it will thus neu- 
tralize the excess of sulphuric acid and add 
to the value of the product. Five to ten per 
cent, are to be added, and w^ell stirred in to 
make a thorough mixture. The whole is then 
transferred to the basin of the kiln, where it 
is left to dry at a very moderate heat, not 
exceeding 180'^ to 200*^ Fahrenheit. 

If there is no excess of sulphuric acid in 
the bi-phosphate, then the best drier is the 
hydrated sulphate of lime, which is deposited 
from the chloride of calcium or mother- 
liquor, treated in Chapter xi. It may be 
added in its pulpy or moist state to the bi- 
phosphate, and the whole must be mixed 
thoroughly by raking. 

When there is any tendency to cake on the 
bottom or sides of the kiln, the mass must 
be kept detached by means of a hoe. The 



X 2 



3o8 PURE FERTILIZERS. 

mass, when dry, is to be dashed into a granu- 
lar powder by means of Carr's Disintegrator, 
previous to being packed into barrels for 
market. 

The product thus obtained is a mixture of 
90 to 95 per cent, of pure soluble bi-phos- 
phate of lime with 10 to 5 per cent, of which- 
ever drier may have been used. 

Formerly, I used finely-powdered mineral 
phosphate of lime as the drier ; but I have 
observed more recently that this substance is 
apt to reduce the bi-phosphate partly into di- 
and tri-phosphates, more particularly when 
there is no free sulphuric acid present. 

The chemical interaction which sets up this 
change is promoted by the incidental water 
of the mixture. Indeed, it is the undecom- 
posed portion of tri-phosphate of lime, which 
exists almost invariably in the ordinary com- 
mercial superphosphates, that causes the bi- 
phosphate portion to ''go back\ according to 
trade language, or become insoluble directly 
in water. 

Although the lift elevator and vacuum vats 
comprise a convenient arrangement for the 
manufacture of soluble bi-phosphate, they 



BI-PHOSPHATE OF LIME. 309 

are not indispensable implements. A much 
simpler plant may be made to answer with 
such an easy material as the "superphos- 
phate", prepared as directed in Chapter xiii. 

This material may be leeched of its solu- 
ble bi-phosphate portion by simply boiling it 
with water in the wash-vat for half an hour. 
Then, by repose, it divides into an upper 
stratum of liquor, which is aqueous bi-phos- 
phate of lime, and a lower deposit of solid 
hydrated sulphate of lime. The former is 
drawn off from the latter into the evapo- 
rating pan and reduced to a crystalline mass, 
as directed at p. 306. 

The solid residue in the vat is transferred 
afterwards to the stands (Plate 23), and 
allowed to drain. These draining stands 
are made of wood, and consist of a funnel- 
portion a, perforated with holes throughout 
its lower circumference, and supported by 
the frame-work c. They must be lined with 
a very coarse blanket or straw to prevent the 
choking of the holes with the solid matter. 
As the liquor percolates through, it is caught 
in the troughs b, which conduct it into a 
reserv^oir. 



3IO PURE FERTILIZERS. 

When all the strong liquor which it re- 
tained has passed through, hot water is to be 
poured upon the contents of each filter, and 
allowed to run through. This washing is to 
be repeated a second time, in like manner, 
and the united wash-liquors or drainings are 
then to be reduced with the previous strong 
liquor in the evaporating pan. 

The residual matter of the filters is the 
same as the exhausted matter of the cylindri- 
cal vats ; or, in other words, hydrated sul- 
phate of lime. It is far superior to ground 
plaster for dressing clover lands ; but must 
be thrown out as waste where there is no 
market for it. The " superphosphate" and 
bi-phosphate of this process, unlike the bi- 
phosphate products of other methods of 
manufacture, do not ^' go back'' into tri- and 
di-phosphate after having been put into 
packages. 

It may be as well to note here that it has 
occurred recently to my mind, that the tur- 
bines used in sugar manufactories might 
serve well for separating the liquor from the 
solid portion of the superphosphate in the 
preparation of soluble bi-phosphate by this 



BI-PHOSPHA TE OF LIME. 3 1 1 

process. It may be that the solid portion is 
too fine for this operation ; but, be that as it 
may, the suggestion is worth a practical trial. 
The saving of space, time, and labour, by 
this means, if it can be substituted for those 
prescribed, would be very great indeed. 

One thing is certain, that it would answer 
well for drying the precipitate of the wash- 
liquor ; for there the deposit is coarse crystal- 
lized sulphate of lime, which will allow its 
liquor to go through the holes of the turbine 
without passing them itself. I, therefore, 
will describe this machine. It consists of an 
iron cage A a (fig. 6), placed in the centre of 
an enveloping case b b, of cast-iron, and 
attached to the base of a central and vertical 
axis c c, to which a cog d d' communicates a 
motion of 1200 revolutions a minute. 

The walls of the cage are a fine cullender 
of very solid metal, and into this receptacle 
the stuff to be dried or cleared of liquor is 
to be placed. The machine being then set 
in motion, the very rapid volation drives the 
stuff against the walls, and sends the liquid 
portion through the fine holes. The solid is 
then to be removed for a new charge. So, 



312 



PURE FERTILIZERS. 



also, is the liquor to be drawn out of the 
jacket when it has accumulated sufficiently. 




Fig. 6, 



The machine must be well dried always, 
when it is not in use, in order to prevent its 



becoming rusted. 



BI-PHOSPHATE OF LIME. 313 

It is the utilization of the centrifugal force 
which constitutes the principle of this ma- 
chine and its mode of operation. 

The solution vat, with vacuum filter com- 
bined (PL 22), which has been noted, is a cast- 
iron cylinderyy^ lined with lead or coated with 
stearic pitch, raised upon a brick-work found- 
ation 6>, and held firmly in place by the beams 
i i, bolted to the floor c. The perforated 
diaphragm, which converts it into a filter, 
is in segments k k, supported, first, by means 
of a strong ledge b b, running around the 
inner circumference a a, of the vat ; and, 
secondly, by a central column d, fastened to 
the bottom c, as shown by the cross section 
and plan views, figs. 2 and 3. 

This column carries at its upper surface 
the wooden footstep e for the end / of the 
shaft of the stirrer, and also a flange to sup- 
port the central portion of the segments 
gggg. These segments are cast with ribs 
on their upper face as rests for a plate simi- 
larly cullendered and coated. The interven- 
ing space between this double diaphragm is 
to be filled with clean coarse gravel or a 
blanket of loose texture as a filtering medium. 



314 PURE FERTILIZERS. 

Fig. 4 gives an enlarged view of the 
stirrer, which is of wrought iron and covered 
with lead. Branch pipes s s s, leading from 
the steam-feeder r r, serve for heating the 
contents of the vat to facilitate solution ; and 
they enter from the outside to prevent inter- 
ference with the arms bbb oi the stirrer. 



CHAPTER XV. 



THE MANUFACTURE OF COMMERCIAL SUPER- 
PHOSPHATE OF LIME. 

The usual rough and ready method of pre- 
paring" this fertilizer is to make a mound 
about two feet high and six or eight feet in 
diameter, with a given weight of powdered 
coprolites, rock guano, marlstones, or other 
crude phosphate of lime ; then to shovel out 
the centre, so as to form a bowl with a rim 
or circumference ten or twelve inches thick, 
and fill the hollow with an equal weight of 
brown oil of vitriol previously diluted with 
water. 

This preparation being completed, the 
powder removed from the centre to form the 
bowl is put back by degrees ; that is, by 
shovelfuls at a time, until all has been added. 
By means of a hoe, the mass is mixed next 
into a paste, and incorporated, finally, with 



3i6 PURE FERTILIZERS. 

the dry portion constituting the sides or 
walls of the bowl. It is left then for several 
days ; and, at the end of that time, if it 
should not be dry, it is to be. treated with a 
sufficient quantity of ground gypsum, pow- 
dered mineral phosphate, sawdust, peat, or 
kindred powder to bring it into a dry state. 

Finally, it is broken down to a granular 
powder, by means of one of Carr's Disinte- 
grators, and packed in bags or casks for 
market. 

This slovenly and unscientific mode of 
proceeding gives a product which has the 
important defects of very variable composi- 
tion, great dampness when iron and alumi- 
nium compounds are present, and excessive 
sulphuric acidity. 

The sulphuric acid, although in very large 
excess, by acting upon the lime in this man- 
ner, causes the sulphate of lime which it 
forms, to envelope that portion of the bone- 
phosphate of lime immediately beneath the 
outer surface of the particles of raw material, 
and make a coating sufficiently hard to pre- 
vent the further penetration of the acid. 
Thus a thorough contact of the acid with 



COMMERCIAL SUPERPHOSPHATE. 317 

every particle of the mass becomes impossi- 
ble, and the consequence is, that the acid 
does its work imperfectly. 

Moreover, the quantity of water of dilution 
necessary to moisten the mass sufficiently is 
in excess of the proportion which the chemi- 
cal constitution of the products demands, and 
this excess must be dried out, subsequently, 
by the use of absorbent powders which add 
to the expense of the fertilizer as well as to 
its already attenuated state, agriculturally 
considered, without imparting any counter- 
vailing advantages. 

When operating in open pits the evolution 
of vapours is discomforting always to the 
workmen ; and if coprolites or other raw ma- 
terial containing fluoride of calcium, should 
be under treatment, the emanations during 
the chemical action are positively injurious 
to health. 

In a commercial sense, too, it is desirable 
to give the product as high a fertilizing 
strength as possible, for manures are gene- 
rally distributed from grand manufacturing 
centres into remote and scattered corners of 
country often not very accessible by means of 



3i8 PURE FERTILIZERS. 

railways or other less convenient means of 
transportation. 

A concentrated fertilizer will cost much 
less for packages, packing and freight, than 
one of low grade, and is proportionally more 
economical to the planter, who can temper it 
as may be required, or according to his own 
judgment, at the moment of using it, and 
with dry earth, peat, or ground plaster. One 
or other of these materials is always ready at 
hand in every district of land, and costs little 
or nothing, comparatively. 

To get rid of all the defects just specified, 
and to operate on large quantities of material 
economically as to time and labour, the work 
must be done by machinery. The chief im- 
plements for the purpose are an elevator and 
mixer, such as have been described in Chap- 
ter v, at pages 111-115. The acid reservoir, 
as well as the mixing box, should be pro- 
tected by a lining of thin sheet-lead. 

The acid may be mounted from a reservoir 
or trough below, by means of a lead pump, 
or in carboys, by means of a lift. A given 
weight of the crude phosphate of lime mate- 
rial in fine powder having been dumped on 



COMMERCIAL SUPERPHOSPHATE. 319 

the ground behind the mixing platform, is 
drawn up by the cups of the elevator, as ex- 
plained heretofore at page 112, and dropped 
gradually into the mixer, the stirrer of which 
is now set in motion. 

When the powder is being added, the acid 
must fall upon it with the proper amount 
of water of dilution, so that all may go 
through the mixing operation simultane- 
ously, as well as continuously, but in small 
charges at a time. To this end, the flow of 
acid from the reservoir or the pump, as well 
as that of the water from the hydrant, must 
be regulated accordingly, by means of feed- 
pipes and cocks of suitable bores. The en- 
trance of the acid and water in this manner 
causes a generation of heat, which assists the 
chemical action of the former upon the pow- 
dered phosphate very materially. 

The mass drops from the mixer in a moist 
state, and is conducted into a reception vat 
by means. of an inclined tube, according to 
the manner described in a previous chapter. 
These receptacles or wells should be of stone 
or brick-work, with walls at least twelve 
inches thick, to give strength for resisting the 



320 PURE FERTILIZERS. 

internal pressure of their contents. Twelve 
feet high and eight feet square, are very 
proper dimensions for them. They should 
have a wooden roof covered with felt cloth 
or paper boards, which have been saturated 
with stearic pitch. 

Plate 24 will give the idea of a series of 
eight of these wells under one roof g g. To 
the latter is fitted, by means of a coupling- 
joint, the tube a leading into the chimney 
hearth, for conveying away the noxious 
vapours generated within the vat. 

To prevent the escape of these vapours 
into the factory, the joints of this roof must 
all be kept tight. There must be also an 
opening d d, for the end of the inclined tube 
through which the mixed mass passes into 
the wells. 

The entrance to each vat is fitted with a 
very strong wooden door, about two inches 
thick, well steadied against the wall, as 
shown by ^ <; when the wells are about to be 
filled ; for, otherwise, the semi-fluid mass of 
the interior might press it down and cause 
great inconvenience and loss. 

This prop arrangement c must be movable, 



COMMERCIAL SUPERPHOSPHATE. 321 



SO that the doors can be put aside when the 
wells are to be emptied. 

Brown oil of vitriol of specific gravity 
1700 is the kind of acid to be used. The 
total required will depend upon the composi- 
tion of the raw phosphate material, which 
must have been determined previously by 
chemical analysis. This once known, it is 
only necessary to weigh out the acid in the 
ratio of 1*21 pounds to every per cent, of 
carbonate and of 0"8i pound to every per 
cent, of bone-phosphate of lime in the raw 
phosphatic material. A further quantity, 
equal to about eight to ten per cent, of the 
whole weight of the mineral may be added 
as an excess to provide for contingencies, 
through the presence of fluoride of calcium 
and iron and aluminium oxides and phos- 
phates. 

Many manufacturers who make their own 
acid use a weight of the latter equal to that 
of the raw mineral, but this great excess does 
not benefit the product. 

The water of constitution required for the 
products from each per cent, of carbonate of 
lime and each per cent, of bone-phosphate of 



322 PURE FERTILIZERS. 

lime is 0-36 and o"i2 respectively. But 
the heat of chemical action always dissipates 
a large quantity, and provision against that 
waste must be made by using an excess of 
the equivalent proportion. As, however, the 
brown oil of vitriol contains already a con- 
siderable quantity, it will not be necessary to 
make this excess greater than 20 to 30 lbs. 
for every 100 pounds of this same brown oil 
of vitriol w^hich may be employed. In that 
case, there will be no unnecessary delay in 
the drying of the contents of the wells. The 
mixture of powdered phosphate, acid, and 
water, will reach the wells in such a state of 
inter-action, that it will be found, within ten 
days, a hard mass of thoroughly decomposed 
raw material, consisting of bi-phosphate of 
lime, sulphate of lime, and the insoluble 
matters of the crude phosphate mineral. 

The per cent, of bi-phosphate will depend 
upon the per cent, of bone-phosphate which 
the raw matter contained. The presence of a 
large quantity of alumina in the latter may 
give rise to humidity in the product conse- 
quent upon the formation of sulphate of 
alumina. 



COMMERCIAL SUPERPHOSPHATE. 323 

At the proper time, the doors which close 
the openings are to be removed, and the dry 
mass is then shovelled out and reduced to 
powder by a Carr disintegrator or Howel- 
Hannay mill, and packed for market. 

It is indispensable to the economy of this 
method that the raw phosphate material 
shall be as free from carbonate of lime and 
fluoride of calcium as possible ; for this 
method, unlike the processes of the previous 
chapters, fails to afford a compensating pro- 
duct for the acid wasted by those compo- 
nents. 

If bone-ash has been the basis-material, 
the product from 100 pounds will amount to 
175 pounds, always provided that no excess 
of water or absorbent powders, as driers, 
have been used. This mixed product or 
"superphosphate", as it is called, commer- 
cially, will be made up as follows : — 

Bi-phosphate of lime _ - - 53'00 

Sulphate of lime — from carbonate - ^'^"°°la7-oo 

„ „ „ tri-phosphate So'OO i 

Silica, organic matters, accidental water, etc. I ^- 

— say - - - - 3 



Total amount uf product - I75'00 

Y 2 



324 PURE FERTILIZERS. 



This " superphosphate" will have the com- 
position, per cent., noted at p. 292, Chapter 

XII. 

It is not possible to make a greater strength 
of bi-phosphate in this way, except with cer- 
tain kinds of apatite, phosphorite, and rock 
guanos, which contain a very high per cent, 
of bone-phosphate of lime with very little of 
other than organic matters. 

In such cases, there is little or no dilution 
or degradation of the product by inert mate- 
rials. But even with pure bone-phosphate 
of lime only 75'64 pounds of bi-phosphate 
(CaO, 2 HO, PO5) can be obtained from 100 
pounds of the former by this process ; and, 
at the same time, iio'25 hydrated sulphate 
of lime (CaO, SO3, 2HO) are produced. 
Consequently, its niaximiun product per 
cent, would be only as given at pages 289 
and 300, Chapter xii. 

It must be remarked, that either on ac- 
count of inferior mineral or bad manipula- 
tion, the admixture of absorbent powders or 
fraudulent practices, there is rarely more 
than 25 per cent, of bi-phosphate of lime at 
best, in commercial superphosphate. More 



COMMERCIAL SUPERPHOSPHATE. 325 

frequently, it falls to ten per cent., and even 
lower. 

In corroboration, here is the calculated 
composition per cent, of the best possible 
" commercial superphosphate" that could be 
made with " South Carolina phosphate": — 



Bi-phosphate of lime (CaO, 2HO, PO5) 




- 25-38 


Hydrated sulphate of lime (CaO, SO, 2 


:H0) 


- 52-82 


Iron oxide and alumina - 




- 578 


Organic matter 




- 5-14 


Sand and silica 




- 8-92 


Water 




1-96 




loo-oo 



This analysis represents a product of only 
1556 pounds from 100 pounds of raw mine- 
ral ; that is of the rarest purity ; but in prac- 
tice it would be so much larger from the 
presence of driers, excess of water and acid, 
as to depress the quality of the " superphos- 
phate" at least twenty per cent. 

In Great Britain, generally, the analytical 
report upon a sample gives its equivalent 
value in tri- or bone-phosphate as the real 
content, seemingly, of the bi-phosphate. 
Thus, a sample of superphosphate from 



326 PURE FERTILIZERS. 

bone-ash containing only 31 per cent, of 
actual bi-phosphate will be sold as having 
the richness of 41 '00 per cent.; these latter 
figures expressing the amount of tri- or bone- 
phosphate of lime to which the former are 
equivalent. 



CHAPTER XVI. 



HORSFORD S BAKING POWDER 

This modern substitute for yeast, in the 
manufacture of bread, originated with Eben. 
N. Horsford, Professor of Applied Chemis- 
try in Harvard University, of the United 
States of America ; but it is known in Great 
Britain and on the Continent as the Liebig- 
Horsford Baking Powder. 

It is a mixture of pure bi-phosphate of 
lime (CaO, 2HO, PO5) and bi-carbonate of 
soda (NaO, 2CO2), in chemical equivalent 
proportions. 

To make the acid element, it is necessary 
to have a very pure tri-basic or bone-phos- 
phate of lime. This is to be prepared by 
dissolving bone-ash in a clean wooden vat, 
with quite pure and dilute hydrochloric acid, 
allowing to settle well, drawing off the clear 
liquor into a clean wooden vat, and then 



328 PURE FERTILIZERS. 

adding pure aqua ammonise until there is no 
further precipitation, or rather until the mix- 
ture blues a piece of red litmus paper dipped 
into it. After repose, the clear supernatant 
liquor or aqueous solution of chloride of am- 
monium is to be drawn off, evaporated to 
dryness as crude crystalline ammoniacal 
chloride, and barreled for market. The resi- 
due is then treated with water, stirred, al- 
lowed to repose, and the clear liquor drawn 
off as before, and mixed and evaporated with 
the previous liquor. A second washing, with 
a fresh addition of water, is now necessary to 
remove the last traces of ammoniacal salt, 
and this wash-water must also follow the 
course of the preceding two into the evapo- 
rating pan. 

The precipitate is next transferred to a 
series of filters, and there allowed to drain 
well. These filters are shown by Plate 25: 
a being the wooden support, c the coarse 
linen filtering cloths, and b the wooden pail 
for receiving the filtrate. 

Assuming that the bone-ash under treat- 
ment contains a liberal proportion of bone- 
phosphate and carbonate of lime — that is, 



HORSFORUS BAKING POWDER. 329 

72 -f 9 = 81 — then the quantity of pure hydro- 
chloric acid (specific gravity riyo) required 
for the solution of every hundred pounds of 
ash would be 118 pounds. Should the acid 
be weaker than specific gravity 1*170, a pro- 
portionally greater quantity must be used. 
It will be more convenient and economical to 
make each and every operation with r39 
tons of bone-ash, so that the amount of pre- 
cipitate shall equal very closely one ton of 
tri-basic phosphate of lime. 

The washed and drained precipitate from 
the I "39 tons of bone-ash, is then to be trans- 
ferred to a clean wooden circular vat, fitted 
with a wooden stirrer. This vat does not 
need any cover, nor yet to be coated with re- 
sisting paint, but is to be fitted with a ''blow- 
up'' or open steam-tube. Brown oil of vitriol 
of specific gravity 1700, and made from sul- 
phur, so as to be free of arsenic, is now to be 
poured upon the precipitate in a thin stream 
during constant stirring. It must be diluted 
previously with its weight of water, or, if 
more convenient, this proportion of water 
may be mixed instead with the precipitate in 
the vat. The necessary quantity of brown 



330 PURE FERTILIZERS. 

acid (1700) for the precipitate, which is equi- 
valent to one ton of pure dry tri-phosphate 
of lime, will be sixteen hundred - weight. 
After all the acid is in, and the mixture has 
been well stirred, it is to be left for a week 
or ten days, care being observed to rouse it 
in the interval by frequent stirrings. The 
sulphuric acid abstracts two equivalents of 
the lime to form sulphate of lime, and leaves 
the remaining equivalent in combination with 
the whole of the phosphoric acid as soluble 
bi-phosphate. At the end of this time, the 
decomposition will have been complete, and 
clean water is then to be added, in order to 
thin out the mass. To promote this end, the 
stirrer must be put in motion. The whole is 
now left to repose, in order that the clean 
liquor may rise to the top. This is an 
aqueous solution of bi-phosphate of lime, 
with a little sulphate. All the rest of the 
sulphate of lime remains as insoluble matter. 
It, however, yet retains some of the soluble 
phosphate, which must be washed out with 
fresh water in the manner just described. 
This wash-water, when drawn off, is to be 
mixed with the first or previous liquor. 



HORSFORD'S BAKING POWDER. 331 

To remove all suspended matter the mixed 
liquors must now be strained through a 
filter-cloth of sufficient fineness, or allowed a 
day's repose, in order that it may settle clean. 
The clear runnings are then to be evaporated 
in shallow enamel-lined iron pans, to a thick 
syrupy liquor, at which stage sufficient wheat- 
flour is to be stirred in to convert it into a 
dry powder. These pans A (fig. 7), arc made 




Fig. 7- 

of large size and superior quality, by T. and 
G. Clark and Co., Wolverhampton. They 
can be set in brick- work, over a naked fire ; 
but the drawing represents one with a cast- 
iron jacket B, so that it may be heated with 
steam. The price of the latter, with fittings, 
is £^\ 10 for one of 25 gallons capacity; 



332 PURE FERTILIZERS. 

^\\ for one of 50 gallons capacity; and 
^11 for one of 100 gallons capacity. 

It is necessary that the powder shall be 
perfectly dry when cold, because any con- 
tained moisture would cause it to act prema- 
turely upon the bi-carbonate of soda with 
which it is next to be mixed. The powder 
would thus become stale, as it were ; or, in 
other words, inert, as a yeast substitute. 

The proportion of bi-carbonate of soda to 
be mixed with the bi-phosphate of lime is 
o"965 pound for every per cent, or pound of 
bone- or tri-phosphate of lime represented 
by the acid powder of bi-phosphate of lime. 
To the ton, therefore, produced, as just di- 
rected, there must be added eighteen hundred- 
weight and three-quarters of bi-carbonate of 
soda. Complete mixture of the two powders 
must be made by means of a Howel mill, 
kept well clean, interiorily, for the purpose. 

The baking-powder is then ready to be 
packed in glass bottles with cork stoppers, 
containing in their centre a wooden measure 
for holding sufficient powder to produce the 
rising of two pounds of fine white flour. 
This sufficient (quantity is one ounce. The 



HORSFORUS BAKING POWDER. 



333 



form of this stopper is shown by fig. 8, in 
which b represents the cork exterior, and a 
the interior wooden measure. This arrange- 
ment is not only convenient for packing, but 
also for the consumer, who would need, 
otherwise, a pair of scales to weigh out the 
proper quantity at each and every baking. 

The two powders may be packed and sold 
in separate bottles, to be mixed at the 
time of use. In such case, the measure- 




Fi2. 8. 



stopper of the bottle containing the acid 
powder must have the capacity for exactly 
one half ounce. On the other hand, the 
stopper-measure of the other bottle must 
hold fully one half ounce. In all cases, the 
measure must be ^^ struck''', that is, the con- 
tents are to be level with the top, for which 
purpose any excess must be scraped off with 
a knife, so as to leave a smooth flat surface. 



334 PURE FERTILIZERS. 

Directions for Use. 

The flour having been sifted into a clean 
wooden bowl, is to be incorporated dry with 
the mixed powder in the proportion of one 
ounce for every two pounds of flour. Or, if 
the acid and alkaline powders are separate, 
then one half ounce of the first, and rather 
more by a grain or two of the latter, are to be 
used to every two pounds of flour. After 
thoroughly incorporating the whole by means 
of the hands, and throwing in a little table- 
salt, sufficient cold water or milk is next 
added to make a soft and rather thin dough. 
In the meantime, the pans must be made 
warm and the oven quite hot. Then, after 
having kneaded the dough only so much as 
is necessary to make it perfectly homogene- 
ous, it is to be put into the pans so as to 
leave about one-fourth of the top space free, 
and baked immediately. Thorough baking 
is indispensable to prevent doughiness of 
the crumb portion of the bread when stale or 
cold ; and, therefore, the loaves must not be 
removed from the oven until they are quite 
brown. 



HORSFORUS BAKING POWDER. 335 

The pans should be of tin plate and round, 
about six or seven inches in diameter, and 
three to three and a half inches in height. 

The bread as thus made from white flour 
is light, sweet, and very superior. Care 
must be taken not to use less than the pre- 
scribed quantity of flour for the bread; other- 
wise, the latter will have a peculiar saline 
taste. Two pounds of good flour yield from 
three to three and a quarter pounds of baked 
bread. 

The chemical action which takes place in 
the mixture of flour, baking-pow^der, and 
water, is as follows : — the bi-carbonate of 
soda neutralizes the bi-acid equivalent of the 
bi-phosphate of lime, and phosphate of soda, 
v/ith precipitated phosphate of lime, is 
formed. Carbonic acid, being thus disen- 
gaged as gas at the same instant, rises 
through the dough, expands it, and makes it 
light and porous. 

There is no loss of flour as by the process 
of raising by yeast. Moreover, the phos- 
phates separated by the bran arc thus re- 
stored to the flour. 



336 PURE FERTILIZERS. 



Brown Bread. 

The ordinary bran-meal, and also the 
"whole ground flour", will make very supe- 
rior bread with this powder, both as to light- 
ness and agreeable taste. A little salt must 
be added ; and, to prevent doughiness of the 
crumb part, the proportion of powder must 
not be less than one ounce of the mixed pow- 
der to two pounds of whole ground flour. 
Even as much as two and a quarter ounces of 
mixed powder may be used with four pounds 
of the flour without imparting any perceptible 
saline taste to the bread. This bread keeps 
well, and is far superior to that made from 
the same flour by any other method of 
raising. 

The ordinary bran-bread meal requires, at 
furthest, only one ounce of mixed powder 
with two pounds of meal. 

The precautions directed already, as to the 
baking, are to be observed more strictly with 
regard to these brown breads than to those 
from fine white flour. 



HORSFORHS BAKING POWDER. 337 

Gout-Bread and Confectioners Cakes. 

The preceding mixed powder, with a cer- 
tain amount of sesqui-carbonate of ammoniae 
in place of a portion of the bi-carbonate of 
soda, becomes an excellent baking-powder 
for bread suited to gouty patients. Neutral 
phosphate of ammonia (2NH3, 2HO, PO5, 
HO) is thus introduced into the bread, and 
this salt entering the system, keeps in solu- 
tion the uric acid and urate of ammonia, 
which are otherwise painful secretions in that 
disease. At the same time, there is given oif 
a larger amount of carbonic acid than from 
the soda-powder, and this property adapts it 
admirably for making sweet cakes. So long 
as the ratio of carbonate of ammonia is not 
in excess, the bread and cakes will have only 
an agreeable taste and wholesome condition. 

To prepare the powder properly, one hun- 
dred pounds of the dry bi-phosphate of lime 
are weighed and put into a wooden trough. 
Assuming that ten pounds of flour are con- 
tained as drier in this hundred of powder, 
then there are ninety of acid or bi-phosphate 
of lime to be neutralized. For this purpose 



338 PURE FERTILIZERS. 

72 pounds of finely-powdered sesqui-carbo- 
nate of ammonia (2NH3, 2HO, 3CO2) are to 
be sifted in, and thoroughly intermixed with 
the acid powder. In other words, the equi- 
valent proportion of sesqui-carbonate of am- 
monia is o'8o for every per cent, (ro) of 
pure, anhydrous bi-phosphate of lime. 

In the same manner three hundred pounds 
of the acid powder are to be thoroughly in- 
termixed with 275 pounds of bi-carbonate 
of soda. These two double powders are 
finally mixed and sifted together, so as to 
produce an uniform fine powder. The com- 
pound powder thus formed is the baking- 
powder for gout-bread and sweet cakes. 

One ounce suffices for two and a half to 
two and three-quarter pounds of flour. It is 
to be used in the manner as directed for the 
soda powder, and the same precautions in 
baking are to be observed. 

It is indispensable that all these powders 
shall be kept dry until after they have been 
mixed with the flour previous to making the 
latter into dough. 



CHAPTER XVII. 



S-^-^*i5F^B!«-t-E— 



GERLAND S SULPHITE OF TRI-PHOSPHATE OF 

LIME. 

The action of sulphurous acid upon tri-phos- 
phate of lime has been studied specially by 
Dr. B. W. Gerland, who was the first chemist 
to give it attention ; and to him we are in- 
debted for all of our practical knowledge on 
this interesting and comparatively novel sub- 
ject. 

Sulphurous acid in aqueous solution dis- 
solves phosphate of lime with considerable 
energy ; more particularly when the latter is 
in an artificial precipitated state. The natural 
mineral forms of it are only less soluble than 
the artificial, and in proportion to their 
greater or lesser density of structure. The 
resulting solutions are perfectly clear, and 
contain phosphoric acid and lime in the same 
proportions as the original substance. 

Z 2 



340 PURE FERTILIZERS. 

As sulphite of lime is very largely insolu- 
ble^ in water, even though the latter may be 
saturated with sulphurous acid, it is evident 
that this salt cannot have been formed ; and, 
therefore, the sulphurous acid must have 
dissolved the phosphate of lime without de- 
composing it. The sulphurous acid thus 
acts quite otherwise than sulphuric acid, 
which latter, under corresponding circum- 
stances, would produce sulphate of lime, to- 
gether with bi-phosphate of lime. 

The relative energy and proportion in 
which the different forms of tri-phosphate 
of lime are dissolved by an aqueous solution 
of sulphurous acid are shown by the follow- 
ing table. The solutions were obtained by 
suspending the phosphate material in water 
and passing sulphurous acid gas through 
the mixture. One thousand cubic centi- 
metres of the solution, made in this manner, 
were found to contain : — 



* Gerland's estimate is, that lOO cubic centimetres of 
the saturated solution contain 8-996 grammes of sulphur- 
ous acid and 0-258 gramme of lime, which arc equivalent 
to 0-553 gramme of sulphate of lime. 



SULPHITE OF TRI-PHOSPHATE. 



341 



Components. 


Pure Pre- 
cipitated 

Triphos- 

phate of 

Lime. 


Bone 

Ash. 


Bone 
Ash. 


Pieces 

of 
Bone. 


Pieces 

of 
Bone. 


Pieces 

of 
Bone. 


Pieces 

of 
Bone. 


Pieces 

of 
Bone. 




grammes. 


grammes. 


grammes. 


grammes. 


grammes. 


e;rammes. 


grammes. 


grammes. 


Sulphurous acid 


218-38 


141 82 


159-446 


36-019 


36-848 


35 597 


33-536 


32-550 


Sulphuric acid 


0-70 


trace 


— 


1-664 


1-748 


2-058 


1-320 


I -185 


Lime 


101-79 


59-69 


51-374 


20-787 


19-233 


20-496 


18-589 


19-350 


Magnesia 


— 


2-79 


2-896 


0-582 


0-460 


trace 


trace 




Phosphoric acid 


8289 


47-42 


40-093 


15-287 


14-508 


15-925 
74-076 


15030 


14-451 


Total 


40376 


251-72 


253-809 


74-339 


72-796 


68-475 


67-536 


Specific gra- ) 
vity of the > 


I -3000 
at 


1-1708 
at 


I -1881 

at 


I -0650 
at 


I -0600 
at 


I -0680 
at 


I 061 1 

at 


I -0612 

at 


solution - \ 


48 -2°?. 


53-3°F- 


57-i°F. 


6i' F. 


63° F. 


64-2°F. 


50° F. 


46-2°F. 



These results show that in the stronger 
solutions there is one equivalent of tri-phos- 
phate of lime to six equivalents of sulphur- 
ous acid ; while those which are weaker con- 
tain the latter in the ratio of only five equi- 
valents to one of tri-phosphate. 

The solutions prepared from bone-ash and 
bone-dust contain more lime than their con- 
tent of phosphoric acid requires to form 
tri-phosphate ; but the proportion of these is 
nearly uniform in the bone. 

The following table shows the composition 



342 PURE FERTILIZERS. 

of the excess of bone-ash which was sepa- 
rated from solution No. 3, after having been 
washed and dried : — 



Matters insoluble 


in hydrocl 


liloric 


acid 


- 5-42 


Sulphurous acid 


- 


- 




- trace 


Sulphuric acid 


- 


- 




- 0-29 


Carbonic acid 


- 


- 




- 0-90 


Lime 


- 


- 




- 48-25 


Magnesia 


- 


- 




- trace 


Phosphoric acid 


- 


- 




- 38-59 


Moisture and defi^ 


ciency 






- 6-55 

100*00 



The proportion of phosphoric acid to lime 
is one equivalent to 3-172; whereas the liquor 
No. 3 held them in the ratio of one to 3-268 ; 
and, moreover, the latter contained all the 
magnesia. Although the excess of bone-ash 
had undergone only this slight chemical 
change, the pieces were completely disinte- 
grated and reduced to fine powder. 

These solutions have the odour of sulphur- 
ous acid, but in less degree than an aqueous 
solution of the gas itself; and, on exposure 
to air, their surface becomes covered with 
brilliant crystals. The weaker solutions re- 



SULPHITE OF TRI-PHOSPHATE. 343 

main unchanged, in closed vessels, for an in- 
definite length of time; but the stronger ones 
require to be kept at temperatures below 
64^ Fahrenheit, in order to maintain their 
preservation. Above this degree, the latter 
decomposes and drops a deposit which in- 
creases, progressively, for days. This de- 
posit is a mixture of sulphite and di- or 
neutral - phosphate of lime, in which the 
former predominates. At the same time, the 
solution becomes richer in phosphoric acid, 
until finally this and the lime are present in 
about equal molecular proportions. The 
same decomposition will take place even 
during the preparation of the solution, if the 
temperature is allowed to rise above 64*^ Fah- 
renheit. 

When exposed in vacuo, the solutions 
crystallize into well formed hexagonal pyra- 
mids composed of di- or neutral-phosphate 
and sulphite of lime with much water of 
constitution. 

A mixture of variable proportions of di- 
phosphate and sulphite of lime is also preci- 
pitated from the solutions when the latter are 
boiled under reduced pressure, diluted with 



344 PURE FERTILIZERS. 

alcohol, or treated with a current of carbonic 
acid gas. 

Although solutions of phosphate of lime in 
sulphurous acids have the strong tendency to 
form the compounds as just explained, it is 
remarkable that they lose it when heated 
rapidly and boiled under atmospheric pres- 
sure. Thus manipulated, they drop their 
phosphate completely as a definite chemical 
compound of tri-phosphate of lime with sul- 
phurous acid and water, which corresponds 
to the formula sCaO, PO5, SO2, 2HO. It is 
in the form of a crystalline white powder, 
which settles readily, but is very light when 
dried. The residual sulphurous acid escapes 
with the aqueous vapour. 

This compound differs from other sulphites 
in not having any greed for the oxygen of 
the air, as it remains unchanged when wet, 
dry, or heated. It holds its water up to 
284*^ Fahrenheit, and at higher temperatures ; 
then water is given off with accompanying 
vapours of sulphur, sulphurous acid, and 
sulphuric acid. 

The sulphite of tri-phosphate of lime is 
neither soluble in, nor acted upon, by cold or 



SULPHITE OF TRI-PHOSPHATE. 345 

boiling water. Dry chlorine and ammonia 
gases are without effect upon it; and aqueous 
ammonia affects it only slightly. A mixture 
of gaseous ammonia and oxygen or air is 
absorbed gradually by the sulphite, and pro- 
portionately sulphate of lime is formed. Sul- 
phuretted hydrogen turns the sulphites yel- 
low by developing free sulphur. Strong 
acids decompose it, oxalic acid more slowly 
and less perfectly, and weaker acids, like the 
acetic, with little or no energy, unless the air 
has access. A weak aqueous solution of 
iodine, — containing, say i2'69 grammes of 
iodine to the litre, — dissolves the compound 
by promoting the oxidation of the sulphurous 
acid constituent ; and this reaction affords a 
ready means of estimating the same. 

The sulphite of tri-phosphate of lime has 
not yet been made in any other way than 
that just described. Phosphate of lime, when 
digested with its solution in sulphurous acid, 
is not changed ; but the contact disposes the 
latter to form, gradually, sulphite of lime, 
which becomes mixed with the phosphate. 
This change progresses to such an extent, 
within a few days, as to cause a perceptible 



346 PURE FERTILIZERS. 

diminution of the specific gravity of the 
liquor. 

Alkalies and alkaline carbonates throw 
down precipitates from these solutions, which 
differ from the sulphite of tri-phosphate of 
lime in both appearance and composition. 

The Method of Mannfachtre. 

The foregoing explanations will render 
easy the proper understanding of the pre- 
paration of the sulphite of phosphate of lime 
on a practical scale. 

Figs. 9 and lo show the construction and 
arrangement of the necessary apparatus for 
making it at the rate of thirty hundred- 
weight every twenty-four hours. 

The raw phosphate material is to be placed 
in the four wooden cisterns or vats Ci C2 C3 C4, 
and upon a false-bottom b, in order that it 
may not be washed away. If the bone-ash 
or phosphate material is finely divided, it 
yields promptly to the dissolving action of 
the sulphurous acid which is now to be led 
into it ; but, in order to increase the strength 
of the solution progressively, it must be 
pumped repeatedly from these cisterns or 



SULPHITE OF TRI-PHOSPHATE. 347 




Fig. 9. 



348 



PURE FERTILIZERS. 



G^ 



(^ 



035 



l<i 



Is^ 



c^o 



155. 










<% 



'm 






§ 



Fig. lo. 



SULPHITE OF TRI-PHOSPHATE. 349 

vats into the towers about to be described. 
The pipes Pi P2 P3 P4, which are fitted seve- 
rally with taps, and, connected with two 
double-acting pumps a A2, serve to produce 
this circulation, which is to continue until 
the liquor assumes a density of 12'' to 15° 
Twaddle. 

The pumps deliver the liquor at the top of 
the condensing towers, through the spouts 
Sx S2 S3 s^. These latter communicate by 
means of plug-holes with three short spouts 
Ui U2 U3, placed beneath and at right angles 
with them. The latter pierce or extend 
through the sides of the three towers Ti t^ t., 
and allow the liquor to fall upon the sieve 
D, which promotes its uniform distribution. 

The towers are built of flag-stone, after the 
manner of those used for condensing hydro- 
chloric acid, or may be constructed of sheet- 
lead. Each one is fitted, at some distance 
above the bottom, with a diaphragm of lath- 
work E, as a support for the pieces of coke, 
broken tiles or twigs, with which it is to be 
filled. The sulphurous acid is without action 
on these percolating media, and they can be 
placed readily, so as to facilitate the free 



350 PURE FERTILIZERS. 



passage of either gas or liquor through their 
interstices, and, at the same time, produce a 
wide expanse of surface. The towers are fed 
at the top with water which, filtrating through 
the coke, absorbs the gaseous sulphurous 
acid entering at the same time from the sul- 
phur furnace at f. The water thus acidulated 
passes out at the bottom of the towers into 
the wooden cisterns containing the phosphate 
material. 

The sulphurous acid is generated as gas 
by the combustion of sulphur on the re- 
fractory-brick floor of a suitable furnace simi- 
lar to those used in the manufacture of oil of 
vitriol. Sitlphtiretted ores may be substi- 
Htted for siilpJmr ; and this means of con- 
centrating them, by roasting, for more econo- 
mical transportation to distant markets or 
smelting-works, opens a way for the pi^oft- 
able production of the sulphite of tri-phos- 
phate of lime in those remote places where 
crude phosphate material abounds and snl- 
phuric acid is to be obtained only at a cost 
which is too great for its einployment in the 
nsnal processes of manufacturing fertilizers. 

After the gas has entered the first tower it 



f* 



i 



5: 

I 



MORFIT im ihe Mrinii/ncKiiv of'FeHiU-:i 




Sectio n a l Elevati N 
Scale of Feet 



^i-tnr. pn^ D^ijoi LkI. 



%aji!7 iati^iiwKltriiisW™ j 



SULPHITE OF TRI-PHOSPHATE. 351 



ascends to the top, thence passes into the 
next, and pursuing a downward course, 
finally ascends into the third tower, from 
which the uncondensed portion is conducted 
off through the draft pipe g, to the chimney, 
or by means of an aspirator. This coursing 
of the gas brings it into broad contact with 
the water, which, in its turn, is sent through 
the pumps and the system of spouts de- 
scribed already, to the top of the towers, 
whence it spreads itself over the coke and 
arrives eventually at the bottom. 

The liquor in each tower is to be kept 
separate, in order that the contents of any 
one may be passed through either of the 
others, and delivered again into the same 
cistern after having become intermixed. To 
this end there is a cross spout v, v^ V3, with 
plug-holes through which the liquor may be 
conducted into either of the four-length 
spouts Wj W2 W3 W4, each of which communi- 
cates with one of the four wooden cisterns. 

If a cistern is to be thrown out of opera- 
tion for the purpose of emptying it, re- 
charging it, or otherwise, the tap on its pipe 
must be turned off. 



352 PURE FERTILIZERS, 

When the liquors have reached 12° to 15° 
Twaddle, they are to be conducted thence into 
lead or copper vessels through branch pipes 
fitted with a tap and connecting severally 
with the delivery-pipe of the pumps. Here 
the sulphite-phosphate solution is boiled un- 
til sulphurous acid gas ceases to escape, — an 
operation that will consume about six to ten 
hours. While the excess of sulphurous acid 
is passing off with aqueous vapour, the sul- 
phite-phosphate precipitates. 

The solution contained five equivalents of 
sulphurous acid to one of tri-phosphate of 
lime, and the solid product holds one equiva- 
lent ; therefore, four-fifths of this gas escapes, 
and. must be reclaimed. For this purpose, 
the boiling vessel is fitted with a cover which 
connects with a cooling worm so arranged as 
to allow the condensed water to return to the 
vessel and the escaping gas to pass into the 
condensing tower ; for, in open vats, the 
concentration beyond 15° Twaddle wastes 
both time and sulphurous acid. 

The sulphite-phosphate settles readily as it 
forms, and at the end of the boiling is to be 
collected on a drainer, pressed and dried. 



SULPHITE OF TRI-PHOSPHATE. 353 

It is then ready for market, and has the form 
of a clean white powder, which neither 
dirties, tarnishes, nor corrodes, and is, more- 
over, harmless to the taste and touch. 

Its Disinfect ijig and Fertilizing Properties. 

This product is both an effective fertilizer 
and potent disinfectant. Its insolubility in 
water and fixedness in air heretofore noted, 
would seem to conflict with such a character ; 
but it happens, fortunately for these pur- 
poses, that this stability refers to the action 
of pure air ; for, in a foul atmosphere, the 
sulphite-phosphate changes gradually into 
di-phosphate and sulphate of lime, and by 
this chemical alteration the air is simultane- 
ously disinfected. The more the air is viti- 
ated and the warmer the temperature, the 
greater will be the energy and rapidity of 
this reaction. An ounce or two of the pow- 
der distributed in the holds of ships and on 
the floors of stables, will remove in a few 
hours the disagreeable odour peculiar to 
those places, as well as arrest the escape of 
ammonia; and a daily renewal of this appli- 
cation will keep them sweet permanently. 

A A 



354 PURE FERTILIZERS. 

In hospital wards and the chambers of the 
sick, it is a most useful purifying agent. 
Animal matter, even if putrid, loses its 
offensive taint when dusted with the powder 
or kept in its neighbourhood. Access of air 
renders its action more decided. The sul- 
phite is always oxidized in these changes, 
and gives very often an ozone reaction. 

It is of special value to the farmer for 
maintaining a pure atmosphere in his stables, 
piggeries, etc., and, at the same time, for 
preventing any waste of the ammoniacal 
emanations from the decomposing dung. 

Dr. J. Dreschfeld, of Manchester, has re- 
ported a series of careful experiments with 
this powder as a disinfectant and deodorizer. 
The results obtained by him were most 
favourable, even in comparison with those 
given by well-known rival substances, which 
were tested at the same time. 

The oxidation of the sulphite-phosphate 
takes place when it is sown in the soil, and 
the decomposition may be expressed by the 
following formula : — 

SCaO, r05, SO2, 2HO + O = 2CaO, PO5, IIO + CaO, 
SO,, 2IIO. 



SULPHITE OF TRI~PHOSPHATE. 355 

The chemical properties of the di- or 
neutral - phosphate thus formed have been 
explained already in Chapter in ; but it has 
a characteristic energy in fertilizing which 
must be re-stated here, as it was determined 
by actual experiment. 

A portion of the sulphite-product, — say a 
layer of one inch thickness, — was buried in a 
stiff clay soil under a loose cover of the 
latter. This soil w^as tested previously for 
lime and phosphoric acid, by boiling it with 
hydrochloric acid ; but it did not show any 
traces of either. After two months — July 
and August — the sulphite-phosphate was ex- 
humed with care to keep it free of any of the 
soil, and finally examined. All sulphite had 
disappeared, and the modified powder was 
found to consist of — 

Sulphuric acid - - 18*59 P^'' cent. 

Phosphoric acid - - 34"S8 „ 

Lime - - - 33-66 

In the original substance there were 34'8 
per cent, of phosphoric acid for 15*8 per cent, 
of sulphuric acid; and if no change, or rather 
assimilation, had taken place, the buried 

A A z 



356 PURE FERTILIZERS. 

phosphate should have contained 14 per cent, 
of sulphurous acid for 24*58 per cent, of 
phosphoric acid: whereas, the analysis shows 
i8'59 per cent, of SO3, or an excess of 41 per 
cent. This excess proves that the moisture 
of the soil dissolved the newly-formed di- 
phosphate at a quicker rate than that at 
which it took up the sulphate of lime. 

In employing the sulphite-phosphate as a 
fertilizer, it is expedient to mix it with other 
manurial matters, and more particularly those 
of organic nature, as its solubility in the soil 
is thus greatly promoted. The commercial 
article contains phosphoric acid in proportion 
equivalent to 70 per cent, of tri-phosphate of 
lime. 

Chemical Analysis. 

The method of analysis is free from diffi- 
culties, and comprises the following steps 
and manipulations : — 

1. Weigh one gramme on a counter- 
balanced watch-glass, and dry in an air- 
chamber at 248° to 284° Fahrenheit. The 
loss of weight represents moisture. 

2. Take a fresh quantity of one gramme, 



SULPHITE OF TRI-PHOSPHATE. 357 

place it in a glass flask of about 150 c. c. 
capacity, add boiling dilute hydrochloric 
acid, cover the mouth with a funnel, and boil 
rapidly until all the sulphurous acid is ex- 
pelled. If there should be any insoluble 
residue it is to be collected on a filter, dried, 
ignited, and weighed. The filtrate is to be 
treated, now, with solution of chloride of 
barium, and the precipitate thus thrown 
down is to be filtered off and determined. 
Its amount corresponds with the quantity of 
sulphuric acid contained in the substance ; 
for ordinary precaution will prevent any in- 
crease through the oxidation of some of the 
sulphurous acid during the manipulation. 

3. Weigh another gramme of the sulphite- 
phosphate powder, place it in a beaker glass 
with some water, and treat it, drop by drop, 
with a standard solution of iodine. At first, 
the colour of the iodine disappears rapidly, 
and the powder loses volume by degrees, 
until only a few grains remain. From about 
this point, the decoloration of the iodine 
liquor proceeds very slowly; but the addition 
of a few drops of hydrochloric acid will 
hasten the action to immediate completion. 



358 PURE FERTILIZERS. 

This small quantity of acid has no influence 
on the result. From the measure of iodine 
solution consumed, the quantity of sulphur- 
ous acid is to be deduced by calculation. 

4. Another fresh gramme of the powder is 
to be dissolved in a little hydrochloric acid 
and water, then heated until all the sulphur- 
ous acid is expelled, next neutralized exactly 
with ammonia, and mixed finally with acet- 
ate of soda. If iron is present it falls now 
as phosphate, and must be filtered off. The 
filtrate is to be dosed with oxalate of soda, 
which precipitates the lime as oxalate in a 
granular form, and easy to be filtered ; but 
the whole should stand twelve hours pre- 
vious to filtration. The latter operation is 
rapid when the liquor is hot at the time of 
adding the oxalate. 

5. From the filtrate, magnesia is to be 
precipitated by the addition of a large excess 
of ammonia ; and it carries down at the same 
time some of the phosphoric acid. 

6. and lastly. The residual phosphoric acid 
is to be precipitated from the preceding 
magnesia filtrate by the addition of an am- 
moniacal solution of sulphate of magnesia. 



SULPHITE OF TRI-PHOSPHATE. 



359 



The following analytical table shows the 
composition, thus determined, of the several 
samples of sulphite-phosphate powder noted 
in the table at p. 341 : — 



Constituents. 


I 


2 


3 


4 


5 


6 


Sulphurous acid - 


1558 


15*69 


1414 


i8-oo 


14-440 


21-139 


Sulphuric acid 


023 


084 


4-46 


274 


I -192 


1704 


Phosphoric acid - 


34-80 


33-87 


31 -22 


28-69 


34-215 


36547 


Lime - 


3989 


4076 


4023 


40 22 


40925 


42-313 


Magnesia 


— 




trace 


0-21 


trace 


1-184 


Sand - 


— 


— 


0-46 


066 


— 


— 


Water, accidental 
,, constitutional 


0-66 
908 


{ 9 '24 
100 00 


9-46 
1 00*00 


10 00 


9 228 


7-"3 


Total - 


100-24 


10052 


1 00 00 


100-00 



According to the formula sCaO, PO^, SO2, 
2 HO, the calculated composition of the sul- 
phite-phosphate of lime is, — 



Sulphurous acid 
Phosphoric acid 
Linie 
Water 



- 15-61 

- 3463 

- 4098 

- 878 

1 0000 



CHAPTER XVIII. 

ON THE CHEMICAL TREATMENT OF " REDONDA 
guano", "ALTA vela guano", and THE 
MINERAL PHOSPHATES OF ALUMINA AND 
IRON GENERALLY, FOR THEIR CONVERSION 
INTO FERTILIZERS. 

These stony substances, erroneously classi- 
fied in trade as " Rock Guanos", were un- 
known until a comparatively recent period. 
Their obdurate character, in both physical 
and chemical senses, rendered them at first 
unsaleable. But time and study improved 
their character, and now that science has ani- 
mated them with her Promethean fire they 
enjoy a life of commercial activity. At pre- 
sent, '' Redonda Guano'' and '' Alta Vela 
Guano' are the only representatives in com- 
merce of this class of materials ; but others 
have been discovered, and will be broui^ht 



PHOSPHATES OF ALUMINA & IRON. 361 



forward, sooner or later, as demand may in- 
crease. 

Both take their names from the place 
whence they are brought. The first has its 
source in Redonda, one of the Leeward 
Islands, lat. 16^ 55' N., long. 62° 18' W. ; 
and the second comes from Alta Vela, an 
island near St. Domingo, in lat. 17° N., long. 
170 W. 

The annexed analytical table shows their 
composition per cent., and also that of seve- 
ral kinds from a source not yet made public, 
but which has been noted to me by a corre- 
spondent as ''A. R. B. phosphate rock\ 

Part of the water present is constitutional, 
and the "Alta Vela Guano" may be con- 
sidered, mineralogically, as Gibbsite. The 
very much higher ratio of phosphoric acid to 
the alumina in Redonda Guano and A. R. B., 
gives them a distinct feature in that respect, 
and assimilates their formula to that for 
pyrophosphate of alumina, which is 2AI2, O3, 
3PO5, loHO (dried at no"). 

The instructions about to be noted will 
apply equally well to all the members of this 
class. 



362 PURE FERTILIZERS. 

Very little of the " Redonda" has come 
forward to this country ; but the importation 
of it into the United States, for the port of 
Baltimore alone, amounted to 4334 tons 
during a recent year. The "Alta Vela" is 
in large supply, owing to the more enter- 
prising management of the business of 
mining and shipping it. This latter, how- 
ever, although a very useful raw material, is 
by reason of its lower ratio of phosphoric 
acid and large proportion of silicious matter, 
the least valuable of the three; for there is as 
much acid, labour, and time required to dis- 
solve it as would be necessary for the solu- 
tion of either of the other two. This is an 
important consideration in making a selec- 
tion for chemical treatment by the processes 
of this treatise. 

The precipitate thrown down by milk of 
lime from the " mother-liquor \ which is left 
by mineral phosphates of lime when treated 
according to the processes in Chapters ix* 



* Sec my patents Nos. 2341-, 2344, 2357, of August 6th, 
7th, and 8th, 1S72. These processes are now leading me 
to a further improvement which will effect the recovery of 



PHOSPHATES OF ALUMINA & IRON, 363 

and X, is so closely allied in its nature to 
the Redonda and Alta Vela Guanos, that 
it may be considered as such for all the pur- 
poses of this treatise. Indeed, it has the 
great advantage of being rather purer and 
having a pulpy state, which latter condition 
renders it soluble instantaneously even in 
cold and diluted acids. 

The chemical agents employed in the fol- 
lowing processes are made to do their in- 
tended w^ork in such a manner as not only 
to add to their original value, but to im- 
prove also the profit on the other mate- 
rials. 

The proportions of acid given are for the 
" Redonda Guano", and must be therefore 
modified for different phosphates according 
to the quantity of alumina and iron which 
they may contain. The larger the propor- 
tion of contained alumina and iron, the 
greater will be the quantity of acid re- 
quired. 



the hydrochloric acid, merely by the evaporation of the 
" motJier-liqiio}'-'' to dryness and subsequent ignition of the 
mass in a suitable furnace. 



3^4 



PURE FERTILIZERS. 



Water 

Water of constitution 
Sand and silica 
Lime - - _ 
Magnesia 
Peroxide of iron 
Alumina 
Phosphoric acid 
Sulphuric acid 
Chloride of sodium - 



Redonda, 
by 

yohnson. 


Aha Vela, 
by 

Voekkcr. 


"A. B. R." 

Average. 


24-67 


4-19 


22-55 





12-99 


— 


1-84 


27-19 


7-95 


•56 


— 


— 


traces 


— 


— 


6- 60 


2-79 


7-14 


21-28 


21-98 


18-54 


43-91 


30-86 


42-23 


traces 


— 


1-35 


traces 


— 


— 


100-00 


1 00- 00 


100-70 



The quantitative relation per cent, of the 
alumina to phosphoric acid is as follows : — 



or- 





"A. B. R." 


Redonda. 


Alta Vela. 


Phosphoric acid 
Alumina - - - 


69-50 
30-50 


32-64 


58-41 
41-59 


— 










"A. B. R." 


Redonda. 


Alta Vela, 


Alumina - - - 
Phosphoric acid 


43-88 
loo-oo 


49-91 

loo-oo 


71-20 
lOO'OO 



PHOSPHATES OF ALUMINA & IRON. 365 

To carry out the processes in connection 
with this mineral, the first step is to reduce 
it to fine powder by any of the means usually 
adopted or prescribed in this work. The 
next is to charge the vat with the necessary 
quantity of hydrochloric acid of specific 
gravity 1170. The construction and arrange- 
ment of the vat, and other necessary appara- 
tus, are shown by Plates 26 and 27. 

The vats are to be mounted upon a brick- 
work support, twelve inches high from the 
ground, as shown by b, w^hich support must 
be covered with a fiag-stone top c, forming 
the bottom of the vats a a a. Surrounding 
the vats and built up to their height, is a 
brick-w^ork enclosure d, forming a hot-air 
chamber e, of six inches diameter through- 
out. As supports alike for the chamber and 
the stone walls of the vats, there should be 
brick pillars or abutments f f at the corners 
of the joints and the centres of each vat. 

The brick enclosure is to be capped with a 
smooth stone laid very level, and kept 
tightly in place by iron bolts fixed tightly 
into the brick-work by means of lead. 

These bolts are to be screw-cut at the ends 



7^66 PURE FERTILIZERS. 



to the length of two inches, and must pro- 
ject above the stone-work, as shown by gg. 

The division stones of the vats are to be 
cut down at the centre of the top side, so as 
to form a passage-way eight inches square 
for accidental overflow from vat to vat, in 
cases of uprising of the contents from violent 
chemical action. 

Each vat is to be provided with a manhole 
I, projecting through the brick-work, for the 
removal of its more solid contents or for 
cleansing it. Also, on the bottom, but in 
the front of the vat, there is to be a drain- 
hole J, of four inches diameter, and fitted 
with a movable plug of caoutchouc in coni- 
cal form, as shown by fig. 1 1 . 



J 



1 



Fi". II. 



Behind this drain-hole, and in an angular 
position, resting upon the interior bottom of 
the vat, is to be a stone covering pierced 



PHOSPHATES OF ALUMINA &' IRON. 167 

with many holes and laid over with straw at 
the commencement of the operation, when it 
is intended, subsequently, to drain the liquid 
dowmwards from the solid portion of the 
charge. 

Holes and plugs similar to those just 
mentioned, but of only two inches diameter, 
are to be placed along the whole height of 
each vat, at intervals of twelve inches apart, 
as shown by ll. These must be fitted by 
means of iron tubes projecting outwards 
through the brick-work, and fixed to the 
stone of the vats by means of a collar and 
molten lead or sulphur. 

The cover of each vat is to be in two 
pieces, the rear part ^r being fixed. The 
other portion is movable, but can be fixed as 
required by means of the bolts and their 
nuts. The fixed part of this cover must be 
of cast-iron, an inch thick, so as to be suffi- 
ciently strong to bear the weight of the work- 
man who may be charging the vat. Its 
under or inner side is to be covered with a 
thick layer of the pitchy matter from the 
stearic candle factories, as a protection 
against the corrosive action of the vapours 
evohed. 



368 PURE FERTILIZERS. 

In this piece the box and passage-way for 
the stirrer o are to be arranged. All parts of 
this stirrer are to be of very hard wood or of 
wrought iron, with arrangement for lifting it 
out when not in operation, as shown at Plate 
26, by means of the chains z z going over a 
pully at the back. Towards the edge and 
near the corner, there is to be fitted a tube Q, 
leading to the fire hearth of the factory 
chimney for conveying away the noxious 
gases as they may arise in the vat during 
the operation. These pipes may connect 
with one larger pipe r, fixed at the back of 
the vats and leading into the fire. 

In the opposite corner, about a foot to- 
wards the centre, there must be a hole of six 
inches diameter for the entry of the acid or 
the powdered mineral into the vat, as may be 
required. This should be fitted with a hop- 
per of hard stone r, about twelve inches 
diameter and six inches deep. The rim 
should be strong and flat to form a support 
for the inverted carboys in the act of their 
being emptied. 

A simple hopper arrangement, as described, 
will answer only when the vat is to be 



PHOSPHATES OF ALUMINA & IRON. 369 

charged first with acid and the mineral is to 
be added afterwards in dry powder. 

On the other hand, if the powdered mine- 
ral is to be moistened with water previously 
to falling into the vat, then the hopper must 
be replaced by the mixer already described 
at p. 1 16. 

To render the vat suitable for general 
service, the cover should be fitted with both 
a hopper and mixer. 

The front part of the cover may be of 
wrought iron plate, a quarter of an inch 
thick or less, and pierced around the edge 
with holes g g for die passage of the bolts 
gg. It must be lined around the inner edge 
with an india-rubber washer, as well as 
coated with stearic pitch on its inner surface, 
so as to form a tight joint and retain an un- 
corroded surface. The bolts gg and the 
holes ^'^' allow the cover to be removed and 
put in place, at will, by the supplementary 
aid of the screw-nuts ^"^''. 

It should be remarked that, in default of 
the cement already noted, the best hydraulic 
cement is the proper material for making the 
joints of the vats ; but, to further protect 

u j: 



3/0 PURE FERTILIZERS. 

them against the action of the acid contents, 
they should be covered over with marine 
glue, or better, with the pitchy residue ob- 
tained in the distillation of fats (mixed with 
a little shellac), and to be bought cheaply at 
the stearic candle manufactories. The mode 
of preparing this latter is described in Chap- 
ter XXVI. 

The vats are to be kept v/arm, when in 
operation, by means of steam circulating 
through the iron tubes s s, arranged in the 
brick chamber. These tubes should be 
covered with stearic pitch, or some equally 
good coating, to protect them against the 
action of acid vapours. 

In the rear of the vats there must be a 
wooden platform apparatus t, Plate 27, to 
facilitate the charging of the vats with the 
acid. That it may be moved readily from 
vat to vat, it is mounted on iron wheels. 

To better explain, however, the operation 
of the lift, the manner of charging the vats 
with acid is as follows. The cage w of the 
lift being lowered to the level of the ground, 
full carboys are then placed on the trolley or 
bogey T T, and the whole elevated by means 



MOB FIT oz 




j[j' ±xi.\'j dfoiy^eii 



'i'riiriiitr & C'r'.SO.Pateruootf-rrxw 



MORFIT on the Mann fa era re of'Fertilixcrs. 



Solution Vat combined with Vacuum Filter. 




Fit. 



Fio.lll 



Plate 22 . 



SCALE OF FEET. 




Pre. IV. 



K 




JpKoi.Ti;-.. desigiiedfwUrMorfiraWork .iil'e 



ViivciilBnulf. Duy*< JJii. LnJi 



IVutiiia- & C^.eO, f ■,iiLTn'.:iU-i' h 



PHOSPHATES OF ALUMINA & IRON. 371 

of the gearing a', until the tops of t are level 
with the top of the vats. At this point, the 
rails on w will coincide with similar ones 
upon a fixed platform running in the rear of 
the vats a a a. The trolley t is then ad- 
vanced until it is opposite the vat requiring 
to be charged, and the carboys emptied 
into it. 

The empties are taken down by the return 
cages. If the powdered mineral is to be 
dropped into the acid dry, it is brought up 
from the ground beneath in the cups v on 
the endless band u of the elevator, which is 
carried by strong wooden supports b'. After 
being emptied from the cups into the hoppers 
c' c', it passes into the vats through the 
adjustable gutters d' d resting one end on the 
hopper r' and the other on supports e' e' spe- 
cially arranged for the purpose. When the 
powder is to be moistened with water or 
acid previously to falling into the vat, it 
must pass through the mixer instead of the 
hopper. 

The proportion of acid will depend upon 
the quantity and composition of the mineral 
to be treated. In this instance of* Redonda 

15 B 2 



■i,-]2 PURE FERTILIZERS. 

Guano", as a standard, for every ton of that 
material about half a ton of hydrochloric acid 
1*170, or its equivalent in weaker acid, must 
be taken. The acid is to be raised in car- 
boys and emptied into the vats by means of 
the lift, as already described in Chapter v, 
or it can be sent up from a reservoir in the 
ground by means of a monte-jus, Plate 10, 
Chapter v. Care must be observed in this 
manipulation to prevent as much as possible 
the escape of acid fumes into the factory, for 
the vats have been designed to promote con- 
venience and comfort in this respect. 

When the requisite charge of acid is in 
the vat, the powdered mineral must be 
mounted by the elevator, and dropped into it 
from the cups during constant stirring. The 
manner of gearing this latter for motion is 
shown at Plate 26. 

All the mineral having entered the vat, 
and the mixing being completed, the whole 
is to be left for twelve hours. At the end of 
this time about yi cwt. of commercial oil of 
vitriol of specific r846, or o\ cwt. of brown 
oil of vitriol of specific gravity 1700, are to 
be added in a thin stream and durimr con- 



PHOSPHATES OF ALUMINA & HWN. 373 

stant stirring. When the acids are added in 
the succession just named, there is little or 
no intumescence. Moreover, all hardening 
of the mass is prevented by adding the sul- 
phuric acid last, and after the preliminary 
action of the hydrochloric acid. 

To effect the prompt and perfect solution 
of the mineral in any other manner was 
found by me to be very difficult on a practi- 
cal scale. 

As this treatment causes much chemical 
action and evolution of vapours, there should 
be frequent halts in adding the acid. When 
all the acid is in the vat, the stirring is to be 
stopped for an hour, and then renewed 
during five minutes. 

The mass is to be thus roused again and 
repeatedly by stirring during the succeeding 
ten to fifteen hours. On the expiration of 
this interval, the mass will have become a 
thick syrupy fluid, which is then to be diluted 
with water, stirred well, and left to repose. 
The water of dilution should not be more 
than half the volumie of the acid liquor. 

To save time in effecting the solution of 
the mineral, steam should be coursing 



374 PURE FERTILIZERS. 

through the tubes which warm the air- 
chamber of the digestion vat, as heat pro- 
motes the chemical action very sensibly. 

If there is any insoluble matter in the 
mineral, it will now fall to the bottom of the 
vat, and leave a clear liquor above. This 
supernatant liquor is a sulphuric-hydrochlo- 
ric solution of the aluminium and iron phos- 
phates, together with more or' less of the 
oxides of aluminium and iron which the 
mineral may have contained. It is to be 
drawn off clear through the plug-holes into a 
wooden vat. 

The construction and arrangement of this 
vat have been described already at p. 127. 

The insoluble matters are to be removed 
through the manhole at the bottom of the 
digestion vat, and thrown aside as waste after 
having been washed once or twice with relays 
of fresh water. 

If, however, as in the case of " Redonda 
Guano", the insoluble matter does not exceed 
several per cent., it may remain, and the next 
operation can go on in the same or digestion 
vat ; and thus very much time, labour, and 
expense will be economized. 



PHOSPHATES OF ALUMINA & IRON. 375 

The liquor, while still in the digestion vat, 
or better, after having been drawn off clear 
into a second vat, is next to be treated, during 
constant stirring, with quick-lime previously 
slaked and made into a smooth milk. This 
neutralizes the sulphuric acid by forming 
with it hydrated sulphate of lime. 

Immediately following the addition of the 
milk of lime, a sufficient quantity of crude 
gas-liquor is to be poured in during constant 
stirring, to throw down all the contents of 
the liquor that can be thus precipitated. All 
of the hydrochloric acid becomes neutralized 
and remains in the solution as chloride of 
ammonia. Much carbonic and bad smelling 
gases are evolved during the reaction ; and, 
therefore, the ammoniacal gas-liquor must be 
added slowly in an open or well-ventilated 
apartment. 

When a red litmus paper, dipped into the 
liquor, may turn blue, it is a proof that 
enough of gas-liquor has been added. 

The precipitate which settles, by repose, 
from the liquor is a greenish-grey-blue pulp, 
consisting of aluminium and iron oxides and 
phosphates, with sulphate of lime and some 
little sulphurct of iron. 



376 PURE FERTILIZERS. 

For loo tons of " Redonda Guano" there 
will be required 33 tons of oil of vitriol, 50 
tons of hydrochloric acid, 20 tons of quick- 
lime, and 300 tons of gas-liquor of 6^ 
Twaddle. The dried product will be, ap- 
proximately, a mixture of 75 tons of gelatin- 
ous phosphates of alumina and iron, 45 tons 
of hydrated sulphate of lime, and 25 tons 
of chloride of ammonium, making a total of 
145 tons. 

The precipitation may be effected wholly 
by gas-liquor, and in such case the precipi- 
tate would be free from lime or its sulphate ; 
but the difficulty is to find a sufficient quan- 
tity of the gas-liquor in any one locality for 
large and continuous operations. 

In all cases the precipitate and its liquor 
are to be drawn off together into a kiln, 
evaporated to dryness, and reduced to a 
granular powder by means of Carr's disin- 
tegrator. As the mass approaches dryness, 
the heat must not exceed 200^ Fahrenheit ; 
otherwise, it will become too hard and gritty. 
It is then ready for market as a fertilizer. 
But to make its agricultural appreciation 
more assured, it should be mixed with ten 
per cent, of bi- or di-phosphatc of lime. 



PHOSPHATES OF ALUMINA & IRON. Z77 

It is very doubtful, however, whether the 
phosphates of alumina, even in their tender 
pulpy state, will ever sustain an active com- 
petition, as fertilizers, with the phosphates of 
lime, so long as the supply of the latter does 
not diminish ; for the preparation of the 
former is expensive, comparatively, and the 
actual measure of their agricultural effect has 
yet to be determined. 

As raw material, however, for the many 
other useful products explained in Chapter 
XXT, they are of prime importance, by reason 
of their abundant supply and moderate price. 



CHAPTER XIX. 

THE MINERAL PHOSPHATES OF ALUMINA AND 
IRON AS RAW MATERIAL FOR THE INIANU- 
FACTURE OF ALUM AND OTHER USEFUL 
PRODUCTS. 

The sphere of industrial utility pertaining to 
this class of substances is a very wide one, 
thanks to the genius and practical skill of 
those men of science who have given the 
subject their special consideration. Many 
and varied are the products which may be 
evolved from them profitably by proper che- 
mical treatment. 

The precipitate obtained from the ''mother- 
liqitor' of acid solutions of mineral phos- 
phates of lime, which is left by the processes 
described in Chapters ix and x, having the 
same nature as the mineral phosphates of 
alumina and iron, may take the place of the 
latter advantageously in all the processes 



ALUAT AND PHOSPHORIC ACID. 379 



about to be described. Being pulpy and 
easily soluble, its use will promote economy 
of plant and facility of manipulations through- 
out. 

Alum and Crude Phosphoric Acid, 
etc., etc. 

The pioneer chemist in these relations of 
the subject is Mr. Peter Spence, of Manches- 
ter, who has published recently a valuable 
process. It is set forth in the following 
description : — 

'' My invention consists in the use of com- 
pounds of alumina and phosphoric acid, such 
as are at present obtained in the island of 
Redonda, near Antigua, in the West Indies, 
and knowm under the name of Redonda Phos- 
phate, and which contain a variable portion 
of iron, and of minerals of similar composi- 
tion obtained in other West India islands 
and other places. These minerals I propose 
to utilize by the manufacture of alum, and by 
obtaining phosphoric acid or compounds 
thereof as by-products for use as manures or 
fertilizers, and for other purposes, such pro- 
ducts, when free, or comparatively so, from 
alumina, being rendered valuable agents for 



38o PURE FERTILIZERS. 

those purposes, especially so as manures or 
fertilizers. The treatment for the aforesaid 
purposes of the said minerals may be varied 
in details, but the following is a description 
of that which I have found to ansvv^er. I 
take the mineral in pieces as it comes to 
hand and calcine it in kilns similar to those 
used for lime, exposing it to a red heat by 
mixing it with coal or coke ; or I take the 
mineral as obtained, and grind it so that it 
will pass through a sieve of, say, twenty 
meshes to the inch ; but I prefer the former 
plan, as it facilitates the solution of the mine- 
ral substance, and renders a portion of the 
iron insoluble by oxidation. The mineral 
having been prepared by these or by similar 
means, I place it in leaden vessels and add 
thereto an equal weight of sulphuric acid of 
specific gravity r6 if the mineral contain 
twenty per cent, of alumina, but only three- 
fifths of its weight if it contain twelve per 
cent., and in similar proportions for other 
degrees of richness. I then apply heat, which 
I prefer to do by blowing steam into the 
vessel containing the mixture. The mineral 
dissolves and^ the specific gravity rises. I 
now cautiously reduce by water or weak 
liquors from subsequent parts of the process 
(especially the washings of the sediment here- 



ALUM AND PHOSPHORIC ACID. 38 1 

after to be mentioned), constantly boiling until 
all is dissolved except the insoluble sediment, 
and the strength of the liquor becomes 9C0 
Twaddle or i '45 specific gravity. I now pass 
this liquor into a close leaden vessel and dis- 
til into it vapour containing ammonia ob- 
tained from gas ammoniacal liquor subjected 
to boiling either by fire or steam injected into 
the said gas-liquor, and the quantity of the 
said gas-liquor I use is equal to 600 to 900 
gallons to each ton of the mineral, according 
to its richness. When all the ammonia has 
been distilled into the mineral liquor I allow 
it to settle for a few hours and then run off 
all the clear solution (now at a strength or 
specific gravity of 1*4, or 80° Twaddle) into 
lead-coolers, to crystallize alum, as is well 
understood; and I allow it to remain in these 
coolers for some days, with frequent stirring, 
in order to obtain all the alum possible, and 
which may be purified by re-crystallization, 
as well known. I find that when the mineral 
contains twenty per cent, of alumina, I ob- 
tain about one and a half ton of alum from 
one ton of the said mineral. The mother- 
liquors having deposited all the alum that 
can be obtained, are now chiefly a solution of 
phosphoric acid with a small quantity of sul- 
phate of alumina, iron, and sulphate or phos- 



382 PURE FERTILIZERS. 

phate of ammonia. This liquid may be used 
directly as a fertilizing agent ; but I prefer to 
take the said mother-liquors direct from the 
coolers and add to them dry sawdust or other 
absorbing agent, just sufficient in quantity to 
absorb all the said liquors, so that none will 
run from the sawdust. I now take the sub- 
stance and dry it at a low heat, so as not to 
char the sawdust, and when dry it forms an 
artificial manure containing phosphoric acid 
and ammonia in such quantities and condi- 
tion as to make it a valuable fertilizer. In- 
stead of ammonia gas-liquor, used with the 
mineral solution to produce alum, salts of 
potash may be used, either alone or in combi- 
nation with ammonia ; of the former, the 
chloride of potassium of commerce, or, pre- 
ferably, sulphate of potash; as, although chlo- 
ride of potassium will yield a sufficient pro- 
duct of alum, the fertilizer would, from its 
use, have a tendency to deliquesce, but sul- 
phate of potash will not have that effect. 
From the above description, it will be seen 
that, by my invention, I obtain as a by-pro- 
duct, a large quantity of phosphoric acid; and 
it has been stated how this may be used as a 
fertilizing agent ; but, independently of that, 
it may be applied to the purposes of producing 
phosphorus in the usual manner, or phos- 



SULPHATE OF ALUMINA. 383 

phoric salts of commerce, as phosphate of 
soda, by adding the required base thereto, 
extraneous matters in the mother-liquors be- 
ing separated, if desired, by ordinary pro- 
cesses of precipitation and crystallization. 
The operations for making alum, above de- 
scribed, leave a sediment of insoluble matters 
which may be washed, and the washings used 
for the reduction of the dissolved mineral, as 
above alluded to. Having thus described 
and ascertained the nature of my said inven- 
tion, and the manner in which it is to be per- 
formed, I desire it to be understood that I 
claim the use of such mineral phosphates as 
aforesaid, for the combined purposes of the 
production of alum and manures, and other 
substances, as mentioned." 

Sulphate of Alumina. 

"Redonda Guano", and other natural phos- 
phates of alumina, have been made the basis 
for the preparation of sulphate of alumina and 
phosphate salts, according to the following 
process by John Berger Spence and Peter 
Dunn : — 

" Our invention consists in a decomposi- 
tion of natural phosphates of alumina, where- 



384 PURE FERTILIZERS. 

by we obtain sulphate of alumina and also 
phosphoric acid or compounds thereof, which 
afford valuable fertilizing agents, or may be 
used for other knowm purposes. 

'* In carrying out our process, we take the 
natural phosphate of alumina, and, having 
broken it (if necessary) into small pieces, place 
it in a leaden or other suitable vessel and 
pour sulphuric acid thereon in the proportions 
of about twelve hundred-weight of sulphuric 
acid to one ton of phosphate of alumina ; but 
the proportion of sulphuric acid may be in- 
creased or decreased, according to the per- 
centage of alumina contained in the phosphate 
of alumina. After digestion for a few hours 
the result will be the formation of sulphate of 
alumina and phosphoric acid ; and, in order 
to separate the alumina from the acid, we in- 
troduce ammoniacal w^ater or the products 
distilled therefrom until the alumina is preci- 
pitated. This substance can then be obtained 
by running off the supernatant liquor from 
the precipitated alumina. We then add sul- 
phuric acid to the precipitate in about equal 
proportions, w^hen sulphate of alumina will 
be formed. The phosphoric acid thus set 
free from the alumina may be collected and 
obtained or combined with any desired base, 
so as to form salts by any of the known pro- 
cesses for so doin<jf. 



PHOSPHATES OF ALUMINA, ETC. 385 

*' The above process may be varied by sub- 
stituting alkaline sulphates or sulphurous 
acid for the sulphuric acid, but in this case 
sulphite of alumina will be produced, which 
will, however, be converted into the sulphate 
by exposure to air, so that it may take up the 
required proportion of oxygen. 

" The process may be varied by the use of 
soda or potash or their carbonates in the 
place of ammonia." 

Phosphate of Ammoitia and Phosphates 
of Lime. 

A further contribution to the practical 
chemistry of the natural phosphates of alu- 
mina has been made recently by John Berger 
Spence and Peter Dunn, in the following 
specification : — 

'' Our invention refers to certain methods 
of treating products arising from the practice 
of an invention, for which Letters Patent were 
granted to Peter Spence, dated Ninth June, 
One thousand eight hundred and seventy, 
No. 1676. 

** According to that invention, the substance 
known by the name Redonda Phosphate and 
other phosphates of alumina, arc used for 

c c 



386 PURE FERTILIZERS. 

the manufacture of alum, and this having 
been crystallized there remains a mother- 
liquor, consisting chiefly of a solution of 
phosphoric acid ; and our invention refers to 
certain methods of treating this mother- 
liquor, in order to obtain substances which 
may be conveniently and advantageously em- 
ployed as manure. 

'' According to our first process, we take 
the said mother-liquors and cause them to be 
absorbed by sawdust or other convenient 
substance, which will, in like manner, hold 
them mechanically ; and we then place this 
material in purifiers of gas-works, or in simi- 
lar apparatus, so that the impure gas shall 
pass through, or in contact with it, as is now 
the case when gas is purified by other sub- 
stances, and this operation is continued until 
all the acid in the said mother-liquor has 
been neutralized by the ammonia compounds 
which have existed in the gas. The resulting 
compound being chiefly phosphate of ammo- 
nia mixed mechanically with the sawdust, is 
available as a valuable manure, or the phos- 
phate of ammonia may be dissolved out and 
thus separated from the sawdust. 

"According to a second process, we distil 
ammonia compounds- from gas ammoniacal 
water into the said mother-liquor, by which 



PHOSPHATE OF AMMONIA, ETC 387 

means we obtain a substance which, as be- 
fore, is chiefly phosphate of ammonia. 

" According to a third mode of treating 
the said mother-liquors, we use them instead 
of sulphuric acid, or to replace a part thereof, 
in the manufacture of superphosphate of lime 
from the ordinary tri-basic phosphate of lime 
of commerce ; and, by using, say, one-half of 
such mother-liquors, together with one-half 
the usual quantity of sulphuric acid, we ob- 
tain a manure much richer in soluble phos- 
phate of lime than by the usual method. 

"Fourthly. We use the said mother-liquors 
to produce therefrom precipitated or insoluble 
phosphate of lime, by adding to such liquors 
as much lime or carbonate of lime as will 
produce neutrality, which condition will easily 
be found by practice, and we thus obtain a 
compound of considerable value as a manure. 

" Fifthly. We obtain from the said mother- 
liquors a soluble, or partly soluble, phosphate 
of lime, by calculating the quantity of lime 
in proportion to the phosphoric acid contained 
in the solution, so that the result may be a 
mono-basic phosphate of lime. As a guide 
for this operation, we may state that when 
the liquors, after the alum is extracted, are of 
the specific gravity of r4 or 80'' Twaddle, we 
find that the quantity of dry slacked lime or 

c c 2 



388 PURE FERTILIZERS. 

hydrate of lime required is i lb. for every 
15 lbs. of the said mother-liquors ; and we 
add the said quantity of lime after having 
boiled the liquors to such an additional 
strength as will produce a friable compound 
in suitable condition to be used alone or 
mixed with other manures. The extent to 
which the liquors are to be boiled down to 
afford this condition will readily be ascer- 
tained by practice. By this process, we find 
that a considerable portion of the phosphoric 
acid is combined with the lime in the state of 
mono-basic or soluble phosphate of lime, 
which is the more valuble condition as a 
manure. 

" Having thus described and ascertained 
the nature of our said invention and the man- 
ner in which the same is to be performed, we 
desire it to be understood that we claim the 
use of the mother-liquors resulting from the 
manufacture of alum according to the patented 
process of the said Peter Spence aforesaid, 
for the production of manure by the processes 
substantially above described, that is to say, — 

" Firstly. By submitting the said mother- 
liquors to illuminating gas during the purifi- 
cation thereof. 

" Secondly. By distilling gas ammoniacal 
water into them. 



TOWNSENUS PROCESS. 389 

" Thirdly. By using them instead of the 
sulphuric acid or a portion thereof employed 
in the manufacture of superphosphate of lime 
from the ordinary tri-basic phosphate of lime. 

" Fourthly. By adding lime or carbonate of 
lime thereto in such manner as to produce 
precipitated or insoluble phosphate of lime= 

** Fifthly. By adding lime in such quantity 
as to produce a soluble or mono-basic phos- 
phate of lime." 

Townsend' s Process. 

Mr. Joseph Townsend, of Glasgow, has 
patented, quite recently, a process for the 
chemical treatment of mineral phosphates of 
alumina, which is worthy of the best con- 
sideration, as it embraces some novel and very 
valuable ideas. I have not yet determined 
its practical economy ; but having previously 
worked in the same direction, there is little 
doubt, in my mind, that any defect in that 
respect, if one may possibly exist, would 
soon disappear through the improving effect 
of practical experiment. The author thus 
describes his invention : — 

"This method has for its object to utilize 



390 



PURE FERTILIZERS. 



and obtain valuable products from phos- 
phates which contain alumina, and which are 
obtainable, or similar to what are obtainable, 
from Redonda, in the West Indies. 

''And in order that the method may be 
properly understood, I shall proceed to parti- 
cularly describe the various processes com- 
prised in it as applied to a phosphate con- 
taining about 40 per centum of phosphoric 
acid and 20 per centum of alumina, and it 
must be understood that when the material 
operated upon contains other proportions of 
the ingredients the processes are to be cor- 
respondingly modified. 

" By my first process, 50 lbs. of soda or 
75 lbs. of potash, are mixed with the phos- 
phate, and heat is by preference applied either 
by fusion or boiling in about 50 gallons of 
water. After settling, the supernatant liquor 
is run off, or it is filtered, and the phosphate 
of soda or of potash that is formed is sepa- 
rated by crystallizing, or by concentrating 
and depositing, when the remaining liquor 
will consist principally of aluminate of soda 
or of potash. When it is aluminate of potash 
that is wanted, aluminate of soda may be 
first formed as described, and the aluminate 
of potash be subsequently obtained by double 
decomposition on adding chloride of potas- 



TOWNSENUS PROCESS. 391 

slum or carbonate of potash. If alumina is 
wanted, its deposition from the aluminate of 
soda or of potash is obtained by injecting or 
otherwise applying carbonic acid. 

" By my second process, 12 lbs. of soda or 
18 lbs. of potash and 47 lbs. of lime are 
added to the phosphate, and by preference 
heat is applied by boiling, whereby aluminate 
of soda or potash and phosphate of lime are 
formed, the former in solution, and the latter 
as a precipitate. 

'' By my third process, 47 lbs. of lime are 
added to the phosphate, and by preference 
heat is applied by boiling, whereby there is 
formed a mixture of alumina and phosphate 
of lime, which can be used as a manure or 
fertilizer. 

'' This mode of utilizing the Redonda or 
similar phosphates containing alumina by 
adding lime to form a phosphate of lime 
usable as a fertilizer, is obviously also appli- 
cable, although the alumina, or more or less 
of it, may have been separated before adding 
the lime. Thus, if the aluminous phosphate 
is first treated with sulphuric acid and sul- 
phate of ammonia or of potash, and the alum 
thereby formed separated, phosphoric acid is 
set free, and, remaining in the mother-liquors, 
may have the lime, or, what will in this case 



392 PURE FERTILIZERS. 

answer as well, its carbonate added to it, and 
so be converted into phosphate of lime ; or 
alum may be obtained by adding chloride of 
potassium and sulphate of magnesia, and 
after it is separated by well-known means the 
remaining liquors will contain phosphoric 
acid, which may be precipitated as phosphate 
of lime, by adding lime or its carbonate, as 
before. 

" By my fourth process, 58 lbs. of lime are 
added, and cause the formation of a mixture 
of phosphate and aluminate of lime, also 
usable as a manure or fertilizer; or aluminate 
of soda or of potash may be obtained from 
the mixture by adding 20 lbs. carbonate of 
soda, or 26 lbs. carbonate of potash, leaving 
carbonate and phosphate of lime usable as a 
manure or fertilizer. If phosphoric acid is 
wanted, nitric, sulphuric, or hydrochloric acid 
is added to the phosphate of soda or of potash 
obtained by the process hereinbefore described 
as my first, which sets free the phosphoric 
acid, forming at the same time the nitrate, 
sulphate, or chloride of the alkali of the 
phosphate, which salt can be separated by 
well-known means ; or a phosphate of an 
earth can be obtained by adding to the phos- 
phate of soda or of potash, lime, magnesia, 
baryta, or strontia, or a soluble salt of any of 
these earths." 



CHAPTER XX. 



THE PHOSPHATES OF ALUMINA AND IRON AS 
RAW :MATERIAL for defecating TOWN- 
SEWAGE. 

The utilization of town-sewage is that para- 
mount problem of hygiene and economics 
which finds a practical solution more nearly 
complete in the use of alumina and iron 
phosphates and oxides than can be accom- 
plished otherwise. 

The sewage of towns is a rich fertilizing 
material, by reason of the nitrogenous or- 
ganic matter which it contains ; but the 
putrefactive tendency of the latter invests it 
with unwholesome influences as to the at- 
mosphere and vegetation. It is, at the same 
time, very bulky, on account of its enormous 
volume of water of dilution.^' In dealing 

* The quantity of sewage entering the Tliames from 



394 PURE FERTILIZERS. 

with it, consequently, there must be such an 
adjustment of the public and private interests 
involved, as will secure the entire separation, 
in profitable form, of all the foreign matters, 
whether dissolved or suspended, as well as 
the deliverance of the effluent water in pota- 
ble condition for mixing with any stream, 
and by means which will not disturb social 
convenience or comfort. 

In other words, the means which are em- 
ployed must be free from engineering diffi- 
culties, very simple as to manipulation, and 
always under control as to economical supply 
and management. Therefore, the defecating 
agent must be from an inexhaustible source 
near at hand, and such a pliable material that 
it can be made to do its work over and over 
again, indefinitely, after having, at each suc- 
cessive operation, previously given up to 
commerce, agriculture, or the arts, that more 
valuable portion which is not needed for de- 



London and its suburbs is computed to be 31,650,000,000 
gallons annually ; and the proportion of solid constituents 
varies from si- to 17 ounces per ton of sewage, according 
to locality. This includes both the suspended matters and 
those in solution. 



MORTIT on the Ma mifkcture oFFertL 






Speciallv liesigiied for D^ Mo4ifs Work on Fertilizers . 



O.PaceiTiosti: 



DEFECATION OF TOWN-SEWAGE. 395 

fecation. However rapidly progressive may 
be the daily consumption of such an agent, 
this constant reproduction of supply will 
fully keep pace with every demand upon it. 

By adopting Forbes's process as the initial 
purifying operation, a long stride may be 
made towards the accomplishment of the 
purposes in view. The alumina and iron 
salts are well known to have the property, in 
characteristic degree, of separating organic, 
sulphuretted, and infectious matters from 
liquors ; and it is only necessary, as Forbes 
prescribes in the case of sewage, to employ a 
solution of any mineral phosphate, like "Alta 
Vela" and " Redonda Guanos", in either sul- 
phuric or hydrochloric acid. This solution 
is made to flow as a thread-like stream 
into the sewage, and so that it may meet, 
concurrently, a thin stream of milk of lime. 
At the moment of contact, the lime neutral- 
izes the acid which holds the alumina and 
iron oxides or phosphates in solution, and, 
consequently, these latter, in precipitating as 
a solid, carry down all the suspended and 
some of the soluble matters of the sewage. 

The precipitate is a valuable mixed matter 



MORFIT on the Manufachvre ofFertiUzrrs. 



Draining Vats perspective view 



^ ^ 



SCALE 



Specially desigtiedfor K Mrfifs Work ai Fertilizers . 



Vincen.tBrooks,Day8:.San. Litli. 



iHate 2;: 




Truimei ,t C°.60,Pacernosa'i 



396 PURE FERTILIZERS. 

which will receive consideration directly ; 
and the clear fluid portion or effluent water 
retains, of its original impurities, only a 
portion of saline ammonia and other salts in 
solution. These must be removed, in great 
degree at least, by further treatment ; and the 
best course in my judgment is to let the 
effluent water flow from the precipitate upon 
beds of peat charcoal. By infiltration through 
these media it becomes quite or nearly sweet 
and pure ; for the chemico-mechanical pro- 
perties of peat charcoal are peculiarly great 
for destroying the septicity of liquors and 
removing any tendency to unwholesomeness. 
Moreover the peat charcoal accomplishes this 
result by increasing its own commercial value, 
as a fertilizer, in degree nearly proportional to 
the amount of saline impurities which was 
contained in the infiltrating effluent water. 

Though I have not yet determined the 
question, actually, it is my impression that 
the capacity of the charcoal for abstracting 
certain saline matters from the effluent 
sewage waters is so great, that it would 
serve for a long protracted period as a filter- 
ing medium. 



DEFECATION OF TOWN-SEWAGE. 397 

In other words, the effluent water may be 
passed through peat charcoal in oft repeated 
fresh currents without producing saturation ; 
and that when saturated with saline matter it 
may be revived by calcination in suitable 
vessels to do its original service over and 
over again an indefinite number of times. 
Its ammonia being given oft; at the same 
operation could be reclaimed by simple con- 
densation and sent to market in pure solid 
form. 

Such a profitable mode of making the 
charcoal a self sustaining material on the 
spot would endow the enterprise of purifying 
and utilizing sewage with both scientific and 
practical perfection. 

No sewage is fit for any process of filtration 
or irrigation until the sludge has been pre- 
viously separated ; and the mass of antiseptic 
filtering medium required for the final treat- 
ment or infiltration of the effluent water, 
will be very materially lessened by using a 
chemical agent as described for purifying the 
liquor, in degree at least, while promoting the 
deposition of the sludge. 

It is always preferable to use hydrochloric 



398 PURE FERTILIZERS. 

acid as the solvent for the mineral phosphate 
in this connection, because sulphuric solutions 
cause the formation of sulphate of lime, which 
renders the sewage precipitate unprofitably 
bulky and weighty. 

I propose, however, to make the sewage 
enterprise independent of all natural phos- 
phates of alumina ; and, indeed, to liberate it 
from the contingencies of a precarious supply 
of any defecating material. To this end only 
the quantity which may be necessary for the 
treatment of the first batch of sewage will be 
required ; and for the purpose, I replace the 
natural phosphate by a new artifical material 
which is, in fact, a waste product at present ; 
being the ''mother-water' as eliminated by 
my processes for the precipitation of pure 
phosphates of lime from hydrochloric solu- 
tions of mineral phosphates of lime described 
in Chapters ix and x. 

It consists of alumina, phosphate of alu- 
mina, oxide of iron, and phosphate of iron, 
in the state of liquor ; and is, qualitatively, 
a counterpart of the acid solution of Alta Vela 
or Redonda Guano, but in superior degree as 
to the quantitative relation of the best consti- 



DEFECATION OF TOWN-SEWAGE. 399 

tuents. Being, moreover, a by-product, it 
saves all the expense and trouble of the acid 
and manipulation involved in the use of Alta 
Vela and Redonda Guano ; is always very 
cheap, and in abundant supply on the spot, 
and releases the sewage-purification enter- 
prises from all dependence upon the con- 
tingencies incident to an imported material. 
Being a hydrochloric solution, the sewage 
precipitate produced by its means has the 
maximum degree of concentration, as will be 
seen by comparing the results in the analy- 
tical table given over leaf. 

The organic matter contains nitrogen in 
proportion equivalent to ij to 2 per cent, of 
ammonia. The figures of the following table 
prove that sewage precipitate under most 
favourable conditions cannot contain more 
than 5 to 10 per cent, of phosphoric acid and 
li to 2 per cent, of ammonia. These are the 
only components of agricultural value, except 
the organic matters. The ammonia gives a 
money expression to it of 24s. to 32s. per 
ton ; and the phosphoric acid associate being 
combined with alumina and iron is worth 
only IDS. to 15s., so that the total value 



400 



PURE FERTILTZERS. 



COMPONENTS. 


Sewage pre- 
cipitate ob- 
tained by 

means of a 

sulphuric solu- 
tion of Alta 

Vela Guano. 
Morfit and 

B.W.Gerland. 


Sewage pre- 
cipitate ob- 
tained by 
means of the 
" mother- 
water", 

Morfit. 


Moisture - - - 
Sand and silica 
Organic matter, insoluble 
Organic matter^ soluble in water - 
Organic matter^ soluble in hy- ) 

drochloric acid - J 
Alkaline and magnesian chlo- 1 

rides and sulphates - J 
Sulphate of lime 
Carbonate of lime 
Lime, combined with organic acids 
Carbonate of magnesia - 
Peroxide of iron - 5-35 
Alumina - - 4-66 
Phosphoric acid - 5*25 


8-6o 

38-04 

8-35 
2-04 

9-37 
•90 

3-18 

12-84 

3-29 

1-07 

I 15-26 


7-20 

36-49 
7-18 
2-15 

9-14 
1-25 

1 5-70 
30-09 


Total 


102-94 


99-20 



would be only 34s. to 47s. per ton. Hence, 
it follows that the use of Redonda and Alta 
Vela Guanos, in the defecation of sewage, 
becomes a profligate application of them 
when the precipitate is to be dried and sold 
as a fertilizer. Greater manurial value would 



DEFECATION OF TOWN-SEWAGE. 401 

be obtained at less cost by the substitution of 
pure phosphate of lime. 

The mineral phosphates, as well as the 
" mother-water", must, therefore, be emanci- 
pated in more profitable forms, after having 
done their work of purifying the sewage ; 
and the practical methods for widening their 
sphere of industrial utility will be the sub- 
ject of the following chapter. At the same 
time, it should be remarked that the organic 
matters, silica, and chemico-mechanical tem- 
perament generally, of the sewage precipitate, 
render it a superior special manure for clay 
soils. 



D D 



CHAPTER XXI. 

THE PROFITABLE UTILIZATION OF THE PHOS- 
PHAT-ALUMINA PRECIPITATE FROM SEW- 
AGE, AS RAW MATERIAL FOR VARIOUS 
PRODUCTS. 

The information about to be set forth refers 
to the profitable utilization, for sundry pur- 
poses, of the alumina-ferruginous precipitate 
that is formed, by means of lime acting on 
solutions of aluminium and iron oxides and 
phosphates in connection with sewage, for 
the defecation and deodprization of the latter. 
It is indifferent whether these are specially 
prepared solutions of a natural phosphate of 
alumina and iron in sulphuric acid, like the 
'*Alta Vela Guano"; or the '' inotIier-Uq2ior\ 
which is left when phosphate of lime is 
separated in a pure state from hydrochloric 
solutions of mineral phosphate of lime, by the 
skilfully adjusted addition of lime, chalk, 



PRECIPITATE FROM SEWAGE. 403 

whiting-, oxide of aluminium, oxide of iron, 
phosphate of alumina, or phosphate of iron 
as the precipitant. 

The precipitate thus formed consists of the 
organic matter which was suspended in the 
sewage, together with phosphate of alumina, 
phosphate of iron, oxide of aluminium, oxide 
of iron, sulphate of lime, and some excess of 
the lime-precipitant ; provided the defecating 
agent or liquor was a solution of "Alta Vela" 
or kindred mineral in sulphuric acid. 

But, if the hydrochloric '' mother-liquor" 
from mineral phosphate of lim^e should be 
substituted for the sulphuric defecating 
liquor, then the precipitate will not contain 
any sulphate of lime. 

Furthermore, the aluminium and iron 
compounds may be precipitated from the 
''mother-liquor ' by means of milk of lime, 
without the intermediation of sewage. But, 
in such instances, the precipitate will be free 
from both sulphate of lime and organic 
matter ; that is, the aluminium and iron 
compounds will be thrown down pure. 

In each case, however, the precipitate has 
a pulpy condition, most easily acted upon by 

I) D 2 



404 PURE FERTILIZERS. 

dilute acids and other chemical agents, and 
is free from all associates which are obstruc- 
tive to the purposes in view. These proper- 
ties give it, therefore, a commercial value 
very much greater than that of the original 
mineral whence it was derived, even though 
the expense of thus improving it may be 
taken into calculation. Indeed, it is their 
application to sewage in the first instance, 
that gives to the mineral phosphates of alu- 
mina and iron their maximum of commercial 
appreciation. 

The precipitate formed with sewage is a 
good manure, qualitatively, by reason of the 
nitrogen and phosphates which it contains ; 
— all of these being in potential conditions 
for promoting vegetation. This effect can be 
realised, however, only by sowing the pre- 
cipitate in its hydrated state ; for, when 
dried into a hard powder by heat above 212° 
Fahrenheit, for greater economy and con- 
venience of transportation, it loses much of 
the sensitiveness of its chemical tempera- 
ment, and becomes less quickly assimilable 
by the growing crops. 

This fact, and the additional circumstance 



PRECIPITATE FROM SEWAGE. 405 

that the alumina and phosphate of alumina 
which it contains may be turned to better 
account for various technical purposes, prove, 
however, that the restriction of this precipi- 
tate to agricultural service, is a waste of its 
capacity for a wider range of utility. There 
need not be any sacrifice in this wider 
application of the nitrogenous organic con- 
tents. 

The economic applications which I pro- 
pose to give this new material, and the 
modes of treating it for them severally, are 
as follows : — 

Firstly. 
Foi^ the Reclamation of its Nitrogenous 
Matter as Mateinal for the Manufac- 
ture of Anwionia Salts. 

The precipitate may be made to give up 
all its insoluble* organic matter for indepen- 

* The whole of the nitrogen could be reclaimed as 
ammonia salt by combustion of the dried precipitate with 
soda lime, as suggested at pages 51-53. The solid residue 
would still be a good material, both for the purposes 
named in page 408, and for the products noted in this 
chapter. 



4o5 PURE FERTILIZERS. 

dent use as an ammonia material. It is only 
necessary to draw off the effluent (sewage) 
water, wash the residue once, then to treat 
the pulpy mass by means of a current of 
steam, and to add hydrochloric acid gradu- 
ally, until the mass is dissolved. A cloudy 
liquor will be the result ; but this liquor, on 
being drawn off from the vat through a 
cloth, leaves its suspended matter upon 
the filter, and runs through as a clear fil- 
trate. 

The contents of the filter are to be washed 
with hot-water, pressed and dried carefully 
in hot-air currents. It consists of the sus- 
pended organic matter of the original sewage 
and precipitate, together with some sulphate 
of lime, if a sulphuric solution of "Alta Vela" 
or other mineral phosphate has been the de- 
fecating agent employed. 

Being composed of organic and sandy 
matters in chief, it would be a very, advan- 
tageous addendum for rendering clay soils 
loamy and rich. It might, also, serve as 
material for the manufacture of ammonia 
salts, as suggested at page 49. 

The clear filtrate which has run from it is 



PRECIPITATE FROM SEWAGE. 407 

the counterpart, in a chemical sense, of a 
solution of "Alta Vela Guano" in sulphuric 
acid ; excepting that it has been made with 
the much cheaper hydrochloric acid, and less 
expensively as to time, labour, or manufac- 
turing items. In this form it is again ready 
for treating crude sewage, and, being a purer 
liquor than a special solution of raw mineral, 
will produce better results. 

But a prime advantage which this mode of 
treatment possesses is, that it will, when re- 
quired, render the great enterprise of sewage 
purification quite independent of any further 
supply of mineral phosphate or " inother- 
liqiior' after that quantity which is consumed 
for the treatment of ih.^ first batch of sewage; 
for it reclaims the defecating agent over and 
over again for the repetition of its service an 
indefinite number of times. In scarcely less 
important degree, it exerts a valuable indus- 
trial influence by thus liberating the mineral 
phosphates of alumina and the '' mother- 
liquor", for an expansive sphere of useful- 
ness. 



4o8 PURE FERTILIZERS. 

Secondly. 

As Material for Ahmi, Pure Phosphates of 
Alttmina, and Pure Phosphates of Lime. 

The precipitate itself, whether made with 
or without the intervention of sewage, is, by- 
reason of its comparative purity and great 
solubility in acids, a most valuable raw mate- 
rial in the manufacture of alum, crude phos- 
phoric acid, pure phosphates of alumina, 
pure bi-, di-, and tri-phosphate of lime, and 
pure aluminate of soda as a ready saponifier 
for making superior soap. 

It has, also, the capacity for being made 
to replace silicate of soda as a cheapener of 
common soaps. All of these products are in 
great request, though few of them have yet 
appeared in the market to any large extent, 
because hitherto an adequate source of them 
has been wanting. 

The processes of Peter Spence, John Ber- 
ger Spence, Peter Dunn, and Joseph Towns- 
end, for converting '' Redonda Guano" into 
alum and crude phosphoric acid, as already 
set forth, offer means which will apply advan- 
tageously to this precipitate. From this latter 



PRECIPITATE FROM SEWAGE. 409 

all of the phosphates of alumina and lime 
can be made in pure forms most easily and 
profitably by direct combination. 

As a basis of these processes, either the 
phosphate sewage precipitate or the " mother- 
liquor" of mineral phosphates of lime has 
very great advantages over " Alta Vela" and 
kindred minerals in all the relations of manu- 
facturing economy and convenience. 

All that remains to be added in this con- 
nection, therefore, are practical instructions 
for the elimination of the pure phosphate of 
alumina constituent, and for the manufacture 
of aluminate of soda. 

Thirdly and Fourthly. 

Alummate of Soda or Ready Saponifier, and 
Common Salt. 

Aluminate of soda may be made either 
directly from the precipitate or from the solu- 
tion of this latter, when it has been dissolved 
in hydrochloric acid for the separation of its 
organic matter, as explained already. 

Supposing that the clear filtrate which 
runs through from the organic matter is 
taken as the basis, then it is only necessary 



4IO PURE FERTILIZERS. 

to bring it to boiling- by steam-currents, in 
wooden vats lined with lead, and then to 
add soda-ash in just sufficient quantity to 
neutralize the acid and precipitate all the 
alumina and phosphate of alumina. 

This being done, the whole is allowed to 
rest, but must be kept warm by enamelled 
tubes, through which there is a continuous 
circulation of steam. 

Lime, as milk of lime, may be substituted 
for soda-ash without difference as to manipu- 
lations. Caution must be observed to add 
it through a fine sieve, so as to prevent the 
passage into the liquor of coarse particles and 
the presence of any great excess in the result- 
ing precipitate. As soon as the precipitate 
or deposit settles at the bottom of the vat, 
the clear liquor above is to be drawn off into 
a pan and evaporated to dryness. This eva- 
porated mass will be coimnon table salt 
when soda-ash has been employed, and chlo- 
ride of calcium if milk of lime was the preci- 
pitant ; and both have a commercial value. 

In case the hydrochloric acid may have 
contained any arsenic, the chloride of sodium 
product will be similarly contaminated, and 



PRECIPITATE FROM SEWAGE. 411 

the use of the latter must, therefore, be re- 
stricted to the manufacture of soda-ash. 

The precipitate is next to be washed with 
several relays of fresh water and heated by 
steam-currents during each washing. 

When the first wash-water has been re- 
moved, commercial caustic soda of best 
quality is to be added to the precipitate in 
the same vat and during constant ebullition, 
by means of steam-currents. 

By prolonged boiling, the alumina and 
phosphate of alumina become dissolved, 
while oxide of iron and phosphate of iron, 
if any are present, will remain as brown in- 
soluble residue. To provide against any ex- 
cess of soda in the solution, it were better that 
a small portion of the aluminium compounds 
should be left with this insoluble residue. 

Sufficient repose must now be allowed, in 
order that the liquor may settle clear. This 
liquor is an aqueous solution of aluminate of 
soda, containing more or less of phosphate 
of soda with phosphat-aluminate of soda, 
which latter assimilates to the former in pro- 
perties quite near enough for the practical 
purposes under explanation. 



412 PURE FERTILIZERS. 

The liquor needs only to be drawn off into 
a clean pan, and evaporated to the state of a 
thin syrup, and left to cool, in order that 
most of the phosphoric acid may crystallize 
out as phosphate of soda. These crystals, 
being separated by filtration or draining, are 
to be washed and dried for market. The 
"mother-liquor" from which they are drained, 
on being evaporated to dryness, becomes a 
" ready saponifier' or crude aluminate of 
soda. 

When it has reached the consistence of 
a mush in this pan, it is to be transferred 
into other and more shallow pans to cool. 
Thence it is to be packed in sheet-iron boxes, 
about two feet square and twelve inches 
deep, covered with closely-fitting lids. These 
are to be placed in large furnaces, heated to 
low red heat, carefully regulated, so as not to 
destroy the boxes. 

In about an hour, the moisture will have 
passed off, and the contents of the boxes 
will be beautifully white, with a blue tinge, 
possibly. 

After cooling, the contents of the boxes 
are to be emptied into barrels fitted with 



PRECIPITATE FROM SEWAGE. 413 

tight covers and ground in a mill to coarse 
powder as soon afterwards as possible. 

Finally, it is to be packed in paper board 
boxes, the joints and inner surface of which 
are to be fastened and coated with a dense 
aqueous solution of silicate of soda. On 
drying, this leaves a glass-like surface, which 
protects the box from the corrosive character 
of the powder. 

The saponifier should be made of uniform 
composition always, so that a box of certain 
size may contain a sufficient weight to 
saponify a certain weight of melted fat and 
of water measured by the same box twice or 
more times filled. In this manner, weights 
may be dispensed with, to the great con- 
venience of the million ; for this material will 
enable every housewife or servant of common 
intelligence to make her own soap with the 
kitchen fat. 

This saponifier is wholly soluble in water, 
and though the alumina acts the part of an 
acid to the soda base in this solution, it 
holds on by such a feeble tenure that it will 
desert its chemical union upon the slightest 
provocation. Thus, when the solution is 



414 PURE FERTILIZERS. 

brought into contact with the melted fat, the 
latter seizes the soda and water to form soap ; 
which will have a greater hardness than 
usual, by reason of the diffusion through the 
paste of the alumina and phosphate of alu- 
mina which are set free during the saponify- 
ing reaction. 

Even the carbonic acid of the air would 
decompose it, and therefore the packages 
must be sealed around the joints of the cover 
with a narrow strip of paper ; then dipped 
into a hot mixture of resin and pitch, and 
finally covered, while warm, with an envelope 
of strong paper to render it hermetically close. 

Fifthly. 

Pure Phosphate of Alumina. 

If it is desired to make pure phosphate of 
alumina, then, instead of evaporating the 
previous solution of aluminate and phos- 
phat-aluminate of soda, it must be treated 
in the cold with barely enough of sulphuric 
or hydrochloric acid to neutralize exactly the 
soda constituents ; for, at that precise point, 
the alumina and phosphate of alumina will 
become insoluble and precipitate in a pure 



PRECIPITATE FROM SEWAGE. 415 

state. After repose, the clear liquor above is 
to be drawn off, and the precipitate is to be 
washed thoroughly by several relays of fresh 
water kept at boiling temperature by cur- 
rents of steam entering the mixture. Finally, 
it is to be drained on a filter, pressed and 
analyzed to determine the amount of free 
alumina which it may contain. It is then 
ready to be combined with the necessary 
proportion of phosphoric acid for converting 
it wholly into phosphate of alumina soluble 
or otherwise, as may be required. 

The more alumina which the mineral pre- 
cipitate or "mother-water" may contain, the 
greater is its value for these purposes ; and 
thus, by the proposed treatment, they will 
acquire an appreciation per pound where 
they only have it now per ton. 

PJwsphate of Alumina in the Mannfacture 
of Sugar. 

The great advantages of the aluminium 
compounds in the manufacture of sugar have 
been recognized, since a long period, by che- 
mists; but certain objectionable features, per- 



4i6 PURE FERTILIZERS. 

taining to all except phosphate of alumina, 
have prevented their application in that 
art. 

Until later years there was no source of a 
large and regular supply of phosphate of 
alumina at a reasonable price, and hence it 
was only about i860 that it began to be em- 
ployed. It was first introduced by Reynoso 
into the manufactory of M. de Alma, in Cuba 
{Journal de Pharm. et de Chimie, p. 232, 
vol. ii, 1865). The great practical success 
there realized with it as a means of effecting 
the almost absolute defecation of cane-juice, 
has been confirmed more recently by Domi- 
nique, in France, who has reported his ex- 
perience to The Sttgar-Cane of July, 1870, 

P- 415- 

The phosphate of alumina, dissolved in 

phosphoric acid, having been poured into the 

cane-juice, milk of lime is then added. A 

precipitate of phosphate of alumina ensues, 

carrying down with it some alumina, all the 

lime in combined and free states, together with 

the colouring and nitrogenous matters of the 

original juice. The latter is thus left pure 

for concentration, by freezing or heating and 



PRECIPITATE FROM SEWAGE. 417 

crystallization, as it now contains only sugar 
and some normal saline associates. 

The precipitate, on being pressed and 
dried below 200° Fahrenheit, forms a rich 
and valuable fertilizer. 

Phosphate of Ahimina in Dyeing. 

" M. Collas, of Paris, has succeeded re- 
cently in using phosphates as a mordant in 
dyeing and calico-printing. To this end, he 
passes the yarn or the cloth through a weak 
solution of a phosphate in an acid and after- 
Vv^ards through a dye bath or an alkaline 
bath, by means of which the phosphate is 
fixed upon the fibre." (It may be phosphate 
of lime or phosphate of alumina.) 

" The stuff prepared in this manner is 
ready to be dyed with aniline or other 
colours. The stuff thus prepared may be 
passed through a solution of tannin before 
being dyed or printed. Thus, for instance, 
in order to dye in dark colours, the yarn or 
cloth is immersed in a warm and clear de- 
coction of one kilogramme of sumac in four 
and a half litres of water at 84° to 104° Fah- 
renheit, after wliich the stuff is wrung out. 

E E 



41 8 PURE FERTILIZERS. 

It is then to be immersed in an acid solution 
of the phosphate of 50° Baume, for twenty or 
thirty minutes. On being then wrung out 
and washed, it is ready to be dyed. Purple, 
especially, yields fine hues. 

" In order to dye with insoluble colours, 
the cloth is immersed in a mixture of gela- 
tinous phosphate with a solution of gelatine 
in water, at 75*^ to 85^ Fahrenheit. 

" Cochineal lake may be prepared in this 
manner by stirring gelatinous phosphate into 
a filtered decoction of cochineal." 

Phosphate of Aluinina as a Glaze for 
Pottery. 

This salt is in much request by potters, as 
a glaze, and would find a constant, as w^ell 
as ready market, if put forw^ard at a reason- 
able price. 



CHAPTER XXII. 



ON SPECIAL FERTILIZERS AND THEIR 
PREPARATION. 

Practically, the object of fertilizers is to 
cause small areas of land to produce the 
crops of very much larger ones, with the 
least possible amount of labour. 

Chemically, they are the food of plants 
and act in a twofold manner : first, by 
nourishing them directly ; and, secondly, by 
transmuting the inert matters of the soil into 
forms and conditions which will promote the 
growth of vegetation. 

A seed which may be sown, although it is 
the germ of a crop, has no power to vegetate 
and ripen, except through the means of ex- 
ternal stimulants. 

In all the stages of vegetal growth the 
physical structure of the soil is only less im- 
portant than its chemical composition. It 

E E 2 



420 



PURE FERTILIZERS. 



must be neither too porous, like sand, nor 
too compact, like clay ; but should have a 
temperament midway between the two. 
Hence, in many fields it is as necessary as 
the application of fertilizers, to make an ad- 
justment of this nature by suitable mixture 
of different kinds of soil. 

A soil, to be fertile, should contain the 
following elements : — 



Sand 
Clay 
Gravel 



= as its mechanical acrents. 



Organic matters con- 
taining humus 
Nitrates 

Ammoniacal salts 
Potassa 



= as its assimilable and active 
assents. 



Soda 

Lime 

Magnesia 

Oxide of iron 

Oxide of manganese 

Sulphuric acid 

Phosphoric acid (partly soluble) 

Silicic acid (soluble) 

Chlorine 



= as its mineral assents. 



MOB FIT on tlie Manufacture of'Fertli 



^ •■ ' "^ , , ' ' 



FIG I. 



n a , 



M 



-^ 



FIG. 3. 



" V/m^^^ 






% 






Plate 24. 



1 



/i v///- 



i 



Sj-'Pciolly desi^if';] for DT lilorfifs Work on Ferulizei'^ . 



C?.60 PaleiitosurRDW. 



MORFrr on llie M((ii(ifa<tiii-e of'Fertiliters. 



SUPERPHOSPHATE WELLS. 



FIG 1. 



-ft^ 



Fl C. 3 . 



i I I I I 



I. . i 






:^^ 



1 



i 



I 

7////////////////A 



vA_ w///M77m^ ^jmwmm2^^^m^ 



i 



FIG. 2. 



JZ N«K £ 



SCALE OF FEET 



;ilr 



FRO, a & F.ND cLEVATION & SECTIONAL PLAN. 



Ji«>.iallv Jtsigi*UorKlLrfiisW.:#kaif£niU2ei. 



TruhiiTii 0^.60 pakaiiMnrRc«. 



SPECIAL FERTILIZERS. 421 

In addition, there should be a reserve of 
rocks and organic matters, from which the 
decomposing influences of air, time, and the 
soil, will eliminate the foregoing elements at 
later periods, as will be necessary to insure a 
permartent fertility. 

The mechanical portion serves to facilitate 
the passage of water through the soil ; and, 
consequently, to precede its chemical action 
in the premises. This action consists in ab- 
sorbing and dissolving carbonic acid, ammo- 
nia, and other desirable elements from the 
air and the soil, and rendering assimilable by 
these means the elements of the latter, which 
otherwise would remain inert. Thus it 
assists, not only directly, but indirectly, in 
the nutrition of plants, and more particularly 
in the development of their organic portion. 
A clay-soil requires, therefore, to be deeply 
ploughed. 

The inorganic portion derives its constitu- 
tion from the mineral elements of the soil. 

By repeated cropping, a soil becomes ex- 
hausted of its fertilizing elements ; and they 
must be restored, therefore, from time to 
time, by means of deep ploughing, and the 
application of manures. 



422 PURE FERTILIZERS. 

All plants are not alike, either as to the 
quality or quantity of their food ; that is, 
certain species are so far eclectic in this re- 
spect, as to exercise a g-reater avidity for the 
kind which is richest in their predominant 
element. Therefore, each of the great fami- 
lies of plants must be manured according to 
its peculiar appetite. Thus, for example : 
nitrogen and phosphates of lime are the pre- 
ferred nutriment of the cereals, including 
cotton ; nitrogen and potassa are the choice 
of the leguminous class ; and phosphates, 
potassa, and nitrogen that of the roots. The 
gramineous family differs very little from the 
roots in its appetite. 

But even though one of these elements 
may be dominant in distinct or individual 
crops, the latter cannot attain to a normal 
or abundant harvest, unless their peculiar 
food in the soil is associated, in degree at 
least, with all of the other requisite elements. 

The fertilizer is to be applied to the soil 
and intermixed thoroughly with the sur- 
rounding earth from the roots upwards. Its 
components must be in conditions for acting 
together within a given time, in order to pro- 



SPECIAL FERTILIZERS. 423 

duce a wholesome growth of the crops. In- 
deed, it is expedient to have a portion of the 
fertilizer in active forms, so that in the early 
stage of the development of the plants, the 
latter may acquire that vigorous constitu- 
tion which will enable its organs to exert all 
their powers of assimilation and progress to 
a fruitful maturity. 

Saline manures, or those directly soluble, 
are liable to diminish the crops on light soils 
and dry seasons, more particularly when 
they may be mixed in injudicious or ex- 
cessive proportions. The more favourable 
season for applying them, therefore, is a wet 
one, which will promote their thorough diffu- 
sion through the soil. 

Keeping in view the foregoing principles, 
then, the following skeleton formula will re- 
present a fertilizer of just constituent rela- 
tions for general purposes. 

Phosphoric acid _ _ - 35'00 

Potassa - - - - 45-00 

Ammonia ----- 20'00 



1 0000 



These are the prime elements of fertiliza- 



424 PURE FERTILIZERS. 

tion ; but, being always accompanied in 
natural soil or artificial fertilizers with the 
necessary associate elements of plants, they 
constitute a complete manure for any crops. 

The proportion of 250 to 300 lbs. of 
manure containing these three prime ele- 
ments in the percentage ratio above noted, 
will suffice to stimulate an acre of ground 
into the production of an abundant harvest, 
and leave behind some residue for the suc- 
ceeding year's crops. From this reserve, 
however, the predominant element of the 
harvested crops will have been almost, or 
nearly, entirely exhausted. 

This fact must be remembered in the rota- 
tion of crops ; so that in making one kind 
succeed another, the elementary relations of 
the subsequent fertilizer may be modified 
accordingly. In other words, having grown 
a crop of roots this year on a plot of ground 
manured with the normal fertilizer, then, if it 
is desired to prepare that plot the next year for 
a harvest of cereals, care must be observed 
to make the fertilizer richer in phosphate ; so 
as to restore the normal condition of the soil 
which has been disturbed by the peculiar 



SPECIAL FERTILIZERS. 425 

exigency of the previous root-crop as to that 
element. 

Such are the simple rules which should 
regulate the composition and application of 
special fertilizers ; and, if faithfully practised, 
will, with the divine favour of rain and sun- 
shine, eventuate in successful cultivation and 
profitable harvests. 

Normal Fertilizer. 

Bi-phosphate of lime (CaO, 2HO, PO5) - iQ-oo 

Colombian or precipitated phosphate of lime* - 30'00 

Chloride of ammonium _ _ - 25^00 

Chloride of potassium _ _ - 25*00 

Chloride of sodium - - - - 300 

Sulphateof hme (CaO, SO3, 2IIO) - - 7"00 

lOO'OO 



The above formula will serve for any 
plant, as it contains the elements of fertiliza- 
tion in very judicious proportions. Never- 
theless, for special crops it may be modified 
with some advantage, and according to the 



* The fertilizer must be kept dry always when it con- 
tains precipitated phosphate in association with bi-phos- 
phate, otherwise some of the latter might "go back" into 
di-phosphate. 



426 PURE FERTILIZERS. 

examples which will be given after the next 
paragraph. 

Universal Dimger. 

There is a popular general manure made 
in Germany by Hosch and Enderich, which 
has the following composition. It is of a 
greyish-yellow colour, free from strong odour, 
and reddens litmus paper. 



Water - _ , . 


- 1472 


Organic and volatile matters (ammonia, 7'8o) 


- 2681 


Soluble bi-phosphate of lime (CaO, 2HO, PO^) 


- 10-13 


Di- and tri-phosphates of lime 


- 19-48 


Sulphate of potassa 


- 8-46 


Sulphate of lime ] 
Sand, silica, etc. J 


- 20-40 




1 00*00 



Fertilizer for Cereal Crops. 

In this family, comprising wheat, rye, rice, 
Indian corn, barley, and cotton, the prevail- 
ing elements of nutrition are nitrogen and 
phosphate of lime, with a considerable amount 
of alkaline salts. The normal fertilizer 
should, therefore, be modified and composed 
after this formula : — 



SPECIAL FERTILIZERS. 427 



Bi-phosphate of lime 


- 1 5 '00 


Precipitated phosphate of lime 


- 35-00 


Chloride of ammonium 


- 25-00 


Chloride of potassium 


- i8-oo 


Chloride of sodium - 


300 


Sulphate of lime 


4-00 




1 0000 



Fertilizer for Legiuniiious Plants. 

Beans, peas, and other members of this 
family of plants contain potassa, nitrogen, 
and phosphoric acid, as their prevailing ele- 
ments. Therefore, the following formula 
must be observed in preparing fertilizers for 
such crops : — 

Chloride of potassium - - 40*00 

Chloride of ammonium - - 25"00 

Bi-phosphate of lime - - 1500 

Precipitated phosphate of lime - 2000 



100 00 



Fertilizer for Gramineous Plants. 

For the family of grasses, potassa is the 
dominant element ; and next in order are 
nitrogen, lime, and phosphoric acid. Conse- 
quently, a suitable manure should consist 
of:— 



428 PURE FERTILIZERS. 



Chloride of potassium 


-. 


- 30-00 


Chloride of ammonium 


- 


- 25-00 


Sulphate of lime 


- 


- i8-oo 


Bi-phosphate of lime 


- 


- lO'OO 


Precipitated phosphate 


of lime 


- 13-00 


Chloride of sodium - 




4-00 




1 0000 



Fertilizer for Sugar. 

Sulphate of potassa - - . 35*00 

Nitrate of soda _ . _ 40-00 

Bi-phosphate of lime - - lo'oo 

Precipitated phosphate of hme - 15-00 

It is a prevailing idea that alkaline chlo- 
rides should be excluded from fertilizers for 
sugar because of their deliquescing influence 
upon sugar, and it is in conformity with this 
prejudice that the formula has been con- 
structed. But the true and scientific posi- 
tion of the question has been recently set 
forth by E. Feltz {Journ. des Fabricants de 
Sucre, 1870, p. 52), and A. Marschall {Jour- 
nal of the Chejiiical Society, 1870, p. 457). 

The former chemist concludes, from his ob- 
servations, "that uncrystallizable substances, 
whether invert sugar or those classed as 
organic non-saccharine bodies, are the true 



SPECIAL FERTILIZERS. 429 

molasses builders, and that they act as such 
in two ways : ist. By preventing a sufficient 
degree of concentration ; and, 2nd. By ren- 
dering a boiled mass so sticky, that even if 
sugar crystals are formed, they cannot be 
separated from the syrup." 

Marschall obtained results from his expe- 
riments which led to classifying salts as — 
" I St. Negative molasses makers ; 2nd. In- 
different bodies ; and, 3rd. Positive molasses 
makers. The negative molasses makers, or 
bodies which diminish the solvent power of 
water for sugar are, sodic sulphate, nitrate, 
acetate, butyrate, valerate, and malate ; mag- 
nesic sulphate, nitrate, and chloride ; and 
calcic chloride and nitrate. 

" The indifferent bodies which are without 
influence on the crystallization of sugar are 
potassic sulphate, nitrate, chloride, valerate, 
oxalate, and malate ; sodic chloride, carbo- 
nate, oxalate, and citrate, and caustic lime. 

"Positive molasses makers are potassic car- 
bonate (saline co-efficient 3*8), butyrate (saline 
co-efficient cq), and citrate (saline co-effi- 
cient = o"6). Belaine was shown to be a 
negative molasses maker." 



430 PURE FERTILIZERS. 

Haughton Gill {jfournal of the Chemical 
Society, 1871, p. 269) also contributes an in- 
teresting paper on the saline compounds of 
sugar. 

Fertilizer for Root Crops. 

Potatoes, carrots, beets, turnips, and the 
like, require mostly potassa ; next nitrogen ; 
then lime; and, lastly, phosphoric acid. They 
must, therefore, be cultivated with this mix- 
ture : — 



Chloride of potassium 


- 


- 30-00 


Chloride of ammonium 


- 


- 25-00 


Sulphate of lime 


- 


- 20-00 


Bi-phosphate of lime 


- 


- 10-00 


Precipitated phosphate 


of lime 


- 15-00 




100-00 



Nitrate of soda may replace the ammonia- 
cal salts as the source of nitrogen, but five 
parts of the former must be taken in place 
of three of the latter, those being their equi- 
valent proportions. 

All the other elements of fertilization will 
be found generally in the soil ; and the plant 
acquiring full vigour in its early growth from 



SPECIAL FERTILIZERS. 431 

the fertilizers prescribed, will be able to 
assimilate whatever additional nutriment it 
may need from the surrounding sources of 
the earth and air. 

In all cases, the land must have been well 
limed within two or three years, in order to 
rouse, chemically, its organic matters ; but 
not immediately preceding the application of 
the fertilizers by many months. For if the 
lime has not been in the ground long enough 
to have become wholly carbonate, or com- 
bined otherwise, it would cause a waste of 
the ammoniacal salts. 

In connection with this subject, the reader 
will do well to study the instructive paper of 
Dr. Aug. Voelcker, F.R.S., *' On the Produc- 
tive Powers of Soils in Relation to the Loss 
of Plant Food by Drainage", which is pub- 
lished in the yournal of the Chemical So- 
ciety for 1 87 1, p. 276 to 297. 



CHAPTER XXIII. 

FORMULA FOR THE CHEMICAL ANALYSIS OF 
PHOSPHATIC MATERIALS AND PRODUCTS. 

The phosphates of lime which come under 
chemical treatment for conversion into fer- 
tilizers have either an animal or mineral 
origin, but most generally the latter. 

Mineral phosphates differ in composition 
with their source and the care employed in 
preparing them for market. It becomes, 
therefore, indispensable to a well regulated 
system of manufacture, that each and every 
invoice of them which may be intended for 
conversion into fertilizers shall undergo, pre- 
viously, a full chemical analysis. The full 
analysis is particularly necessary, in order to 
distinguish what proportion of the phos- 
phoric acid may belong to alumina, iron, 
and other bases than lime. 

A correspondingly rigorous inspection 



CHEMICAL ANALYSIS. 433 

should be practised also in regard to com- 
mercial superphosphates of lime, and indeed 
all kinds of artificial fertilizers, for the pro- 
tection of the consumer and in the cause of 
honest trade. The necessity for such an ab- 
solute custom will be seen in the very wide 
differences in the samples which may come 
under examination. This great diversity 
between their pretended and actual composi- 
tion-value, is due either to fraud or unskilful 
manufacture, and frequently to both. 

The highest average per cent, of soluble 
bi-phosphate of lime in commercial samples 
is 20 to 25 ; but this strength is peculiar to 
the products of certain manufacturers only. 
More generally they fall below 20 per cent., 
and often as far down as 5 to 10, without 
a corresponding decrease in price. 

The amount of contained soluble phos- 
phate of lime is often represented, in the 
analytical report, by the higher figures of 
bone-phosphate of lime to which it is equiva- 
lent. For example, every per cent, of soluble 
bi-phosphate of lime in the fertilizer is writ- 
ten as I 32, which latter record is a deception, 
having the effect of misleading the purchaser. 

F F 



434 PURE FERTILIZERS. 

As a protection against errors of either 
accident or intention, the following instruc- 
tions in detail are given for the chemical 
analysis of such materials and products as 
come under consideration in this treatise. 
They are arranged to detect and estimate 
any and every element that is likely to be 
present. 

It is merely necessary to add that a certain 
familiarity with chemical principles and 
manipulations is indispensable on the part of 
the operator who may undertake to carry 
through an analysis. 

Bone- Ash, and Mineral Phosphates of Lime. 

All of these substances may be embraced 
in one general formula. The water used in 
the analytical operations must have been 
distilled ; and it is also imperative to have 
the reagents chemically pure. 

Previous to commencing the analysis, one 
or two sheets of blank writing-paper must 
be folded and stitched in book form, as a 
laboratory record or legend of the progressive 
steps of the analysis. 

The first step is to select a fair average 



CHEMICAL ANALYSIS. 435 

sample of about half a pound of the ash or 
mineral to be analysed, mix it well, and 
then reduce wholly to powder about an ounce 
of it. A clean polished mortar, of iron or 
steel, is best for this manipulation. 

I . Accidental Water or Moisttire. 

Fifty grains of this powder are to be 
weighed upon a delicate balance. Besson, 
Rue de la Ferronnerie, Paris, makes a very 
suitable instrument for ordinary work at the 
low price of £^^. But there is certain 
necessary supplementary apparatus which, 
with packing, will increase the cost to about 
£fi. This consists, in part, of two deep watch- 
glasses, agreeing precisely in weight, so that 
one shall be a counterpoise of the other. The 
powder to be weighed is placed in one watch- 
glass ; while the opposite pan of the balance 
contains the duplicate glass as a counter- 
poise, together with the required weights. 
This promotes both a neat and convenient 
manipulation. 

The other supplement is a set of fine 
weights, ranging from 1000 grains to one- 
hundredth of a grain. The larger ones 

F F 2 



43^ 



PURE FERTILIZERS. 



should be of gilt brass, and the smaller ones 
of gilt aluminium. The balance is of brass, 
and should turn, when fully loaded, with the 
hundredth of a grain. This degree of deli- 
cacy must be insisted on when giving the 
order. Fig. 1 2 shows the form of the balance. 




Fig. 12. 

The watch-glass ciy fig. 13, containing the 
50 grains, precisely weighed, is next to be 
placed on a hot sand-bath c, with an inter- 
vening piece of hollow metal tube b, about 
two inches high, as a support, and to form a 



CHEMICAL ANAL YSIS. 



437 



hot-air chamber between the sand and the 
bottom of the watch-glass. The sand-bath 
may be a plain or porcelain-lined iron pie 
dish, containing white sand, and heated by a 




Fig. 13- 

gas-burner d, on a sliding-holder e, so that it 
may be lowered or raised at will upon the 
upright support f f, made of iron. Here 
the powder is allowed to remain over a 
heat not exceeding 212° Fahrenheit, until it 
ceases to lose weight ; and for determining 



438 PURE FERTILIZERS. 

this point, it must be weighed from time to 
time, with its counterpoise-glass always in 
the opposite pan of the balance, until the 
weight becomes constant. 

The constant weight shows a loss, and 
this loss doubled represents the per cent, of 
accidental water or moisture in the original 
sample or raw material. 

If there should be any constituents of the 
mineral containing constitutional water, such 
as sulphate of lime or sulphate of ammonia, 
they will not lose it at the temperature just 
prescribed. 



2. Organic Matter and Constittttional 
TVater. 

The weighed residue is next to be trans- 
ferred, carefully, to a platinum crucible, and 
heated to redness until all volatile matter is 
expelled. 

This is known when, after repeated weigh- 
ings from time to time, the weight becomes 
constant, and a calx free from carbonaceous 
matter remains. Should any carbonate of 
lime be present in the raw material, this 



CHEMICAL ANALYSIS. 439 

would lose some of its carbonic acid at the 
heat prescribed, and thus lead to error. 

As a preventive, the contents of the cruci- 
ble must be cooled, then moistened with 
some drops of aqueous solution of carbonate 
of ammonia, carefully dried, and heated only 
to dull redness for a few moments, so as to 
expel the ammonia without its carbonic acid. 
Restitution of lost carbonic acid being thus 
made to the lime, the crucible is allowed to 
cool and then weighed. The weight thus 
obtained, less that of the crucible, when de- 
ducted from the previous weight, will show a 
loss, and this difference, multiplied by two, 
expresses the per cent, of organic matter and 
constitutional water in the raw material. 
The residue, or calx, multiplied by two, re- 
presents the total per cent, of fixed or earthy 
matters, and is to be reserved, as a, for 
further treatment. 

Fig. 14 shows the mode of burning off the 
organic matter. The platinum crucible a is 
to be closed in the first part of the heating 
to prevent such a strong draught as might 
drive off unburned particles. Later, how- 
ever, the cover must be removed, and placed 



440 



PURE FERTILIZERS. 



as shown by a , so as to promote access of 
air. 

The steel tongs b, of proper form for hand- 
ling the crucible, are shown at the side of 
the gas-burner support. The trivet c, of plati- 




a 




Fig. 14. 



num wire, which is laid upon the ring g of 
the support as a rest for the crucible a, is 
shown by c c . 



p^ 



O 



CO 

ul 

H 




CO 



■-3 



■¥ 



't: 



CO 



-^ 



PQ 



CHEMICAL ANALYSIS. 441 

If, in the progress of the analysis, the 
presence of salts containing constitutional 
water should be developed, — for example, 
sulphate of lime, — then the figures for this 
constituent are to be deducted from the vola- 
tile portion expelled by ignition. The resi- 
due doubled expresses the per cent, of total 
organic matter in the raw material. 

The precise figures for constitutional water 
will be obtained, as directed, a little further 
on, and in proper places. But, supposing, 
for example, that 5*8 are found to be, subse- 
quently, the per cent, of sulphate of lime, 
then, as the constitutional water is 0*2647 for 
every per cent., this proportion is to be de- 
ducted from the weight of organic matter 
and constitutional water. The residue ex- 
presses the amount of organic matter in the 
raw or original material. 

This constitutional water is not, however, 
to be formulated as a separate item, for it 
must be apportioned to the constituents to 
which it belongs, chemically. The manner 
of calculating it to its proper affinities will be 
explained hereafter. 



442 



PURE FERTILIZERS. 



3. Sand and Silica ; Soluble and Insoluble 



Organic Matters. 



Another portion of 50 grains of the pow- 
dered raw or original material is to be placed 
in a clean beaker glass a, fig. 15, drenched 




Fig. 15- 



with pure hydrochloric acid, covered with a 
glass dish or a deep watch-glass d, and 



CHEMICAL ANALYSIS. 443 

digested over a gas flame c, until all the 
soluble matter has been taken up. 

It should be here noticed whether there is 
any effervescence on the addition of the hy- 
drochloric acid or any corrosion of the under 
surface of the glass cover of the beaker, 
for the first would denote the presence of 
carbonate of lime, and the latter that of 
fluoride of calcium. To modify the action 
of the flame, and to diminish the danger of 
fracture of the beaker glass, a fine wire gauze 
of brass or copper should be interposed be- 
tween the former and the latter ; or, better 
still, a sand-bath b may be substituted for 
the direct flame. In either case, when the 
solution is complete, the cover is to be re- 
moved and the beaker glass further heated 
on the sand-bath for the evaporation of its 
contents to dryness. This expels all excess 
of acid, and renders the silica insoluble. At 
this stage, it is to be left to cool; after which, 
the contents are to be moistened with pure 
hydrochloric acid and a little water, and again 
heated on the sand-bath for 15 or 30 minutes. 

Water being now added for dilution, the 
liquor is then filtered upon a weighed or 



444 



PURE FERTILIZERS. 



counterpoised filter. The filtering operation 
is shown by figs. i6 and 17 : a being the 




Y'w. 16. 



paper filter, properly folded; b, the glass fun- 
nel for holding it ; c, the wooden support of 




Fig.. 17. 



the funnel ; and d, the beaker glass, to receive 



CHEMICAL ANALYSIS. 445 

the filtrate or clear liquor passing through 
the filter. White paper, of a porous but 
strong texture, is made both in France and 
Germany, for filtering purposes ; and filters 
of different sizes may be bought ready cut 
at any dealers in chemicals and chemical 
apparatus. The weight of the ash of these 
filters is generally noted on the package. 

A counterpoised filter is one which has 
been weighed, with great precision, against a 
duplicate ; and its use becomes necessary 
for weighing those precipitates which must 
be dried instead of being ignited. Con- 
sequently, the duplicate is to be marked al- 
ways, and dried with its original fellow, 
previous to being put into the opposite scale 
pan at the time of weighing. 

When the contents of the beaker have been 
poured upon the filter, there are still some 
solid particles adhering to the sides and 
bottom of the glass. These must be loosened 
by a feather, and washed out by means of a 
spritz bottle half filled with water. This 
spritz bottle, a, fig. 19, is an ordinary six or 
eight ounce vial, fitted with a cork bored in 
the centre for the passage of a glass-tube. 



446 



PURE FERTILIZERS. 



which must be drawn out fine at one end. 
By blowing through this tube, the internal 
air is compressed, and the bottle being dex- 
terously inverted, its water comes out with 
the force of a strong jet, which may be 
directed upon any desired point. After the 
entire contents of the beaker have thus been 




Fiiz. 1 8. 



Fig. 19. 



poured and spritzed upon the filter, the latter 
is allowed to drain. Hot water is then added 
three or four times, in order to wash out any 
traces of the solution. Each relay of water 
must be allowed to pass through the filter 
before its successor is poured on. 

The filtrate is b, and the filter is c. The 
filter c is to be placed first between the folds 



CHEMICAL ANALYSIS. 447 

of bibulous paper, and then on a dish over a 
hot sand-bath, and there left to dry until it 
ceases to lose weight. The constant weight 
doubled, represents the per cent, of insoluble 
organic matter, sand, and silica, of the origi- 
nal raw material. This having been recorded 
in the legend, the filter and its contents are 
then burned to a calx in a platinum crucible. 
The organic matter is thus destroyed, and 
the calx being weighed, its weight doubled, 
less that of the crucible and ash, of the filter, 
deducted from the previous weight of the 
dried filter, expresses the per cent, of insolu- 
ble organic matter. The calx, multiplied by 
two, represents the per cent, of sand and 
silica. 

The amount of insoluble organic matter 
deducted from the total organic matter pre- 
viously estimated, gives the per cent, of 
soluble organic matter. 

4 and 5. Sulphate of Lime, and Lime. 

The filtrate b having been on the hot 
sand-bath during all the interval, is by this 
time reduced very much in volume by evapo- 
ration, and thus prepared to receive a dose 



448 PURE FERTILIZERS. 

of alcohol about equal to double its own 
volume, which must now^ be added. This 
will render insoluble and precipitate all the 
sulphate of lime which the liquor may con- 
tain. After eight to twelve hours of repose, 
it is to be filtered off and washed, by passing 
several relays of diluted alcohol through the 
filter. The filtrate is d, and the filter is e. 
The latter must be set to dry over a sand- 
bath. 

The filtrate d is next to be treated with pure 
sulphuric acid, added dropwise, until it red- 
dens a piece of blue litmus paper dipped into 
it. This precipitates all the residual lime, as 
sulphate of lime. After eight to twelve hours 
of repose, it is to be filtered off, washed with 
diluted alcohol, and the filter (say f) dried 
between the folds of bibulous paper, over a 
hot sand-bath, as before explained. The 
contents are then to be carefully transferred 
from the paper to a platinum crucible, and 
the filter paper rolled up and laid loosely at 
the top. Heat from a gas flame is then ap- 
plied, so as to produce a low redness, and 
when the paper is reduced to ash and the 
sulphate of lime has been wtII heated, the 



CHEMICAL ANALYSIS. 449 

crucible and contents are to be weighed. 
This weight, less that of the crucible and ash 
of the filter, when doubled, expresses the 
total of lime, except that existing as sulphate 
in the original or raw material. This lime is 
to be apportioned among the phosphoric, 
carbonic, and organic acids, as will be ex- 
plained in the proper places. The filtrate, 
say G, is, in the meantime, set upon the hot 
sand-bath to lose its alcohol by evaporation. 

While this operation is going on, the filter 
E, now dry, is to be ignited and weighed 
after the manner just noted. The nett weight 
doubled, expresses the per cent, of dry sul- 
phate of lime (CaO, SO3) in the original 
material. But as sulphate of lime is na- 
turally hydrated always, it must be recorded 
with its proper equivalent of constitutional 
water affixed, which is 0*2647 for every per 
cent., and makes the formula CaO, SO3, 
2HO. 

All the alcohol having been evaporated 
from the filtrate, aqua ammoniae is now 
added to the residual solution until the 
odour of the reagent is strongly perceptible. 
After six hours of repose, it is to be filtered 

G G 



450 PURE FERTILIZERS. 

and washed with water containing aqua am- 
monias. The long repose is necessary, in 
order that the phosphate of magnesia may 
separate completely by crystallization. 
The filtrate is h, and the filter is j. 

6. Phosphoric Acid. 

The filtrate h contains only the phospho- 
ric acid belonging to lime, and is to be 
treated at 90° Fahrenheit, first with a solu- 
tion of chloride of ammonium, rendered 
strongly ammoniacal and carefully stirred. 
Solution of chloride of magnesium is now to 
be poured in cautiously until a precipitate or 
even cloudiness ceases to form. The whole 
is then left for four or five hours to repose in 
the cold ; after which it is filtered, and the 
filter washed with water, rendered ammonia- 
cal ; then dried, finally ignited, and weighed. 
The precipitate formed is the phosphate of 
magnesia and ammonia (NH3, HO, 2MgO, 
POj, 12HO) ; but, by ignition, it loses its 
ammonia, and becomes pyro-phosphate of 
magnesia (2MgO, PO5). Every per cent, of 
this latter contains o'639 per cent, of phos- 
phoric acid. This phosphoric acid belongs, 



CHEMICAL ANALYSIS. 451 



as before stated, to lime, and must be written 
in the record as tri- or bone-phosphate of 
lime. To make this salt, every per cent, of 
phosphoric acid requires ri66 per cent, 
of lime = sCaO, PO5. This proportion of 
lime is to be deducted from the total lime 
already estimated. 

Fresenius and many other chemists pre- 
scribe an allowance of one and three-quarter 
milligrammes, for every hundred cubic centi- 
metres of the combined filtrate and washings 
from the ammonia-magnesic-phosphate, to 
compensate for an equivalent portion re- 
tained obstinately in solution. But Parnell, 
with whose experience my own agrees, ob- 
serves that such a correction is rendered 
unnecessary by the presence of an excess of 
the strongly ammoniacal solution of mag- 
nesium salt. 

7 . Phosphate of Iron . 

The contents of the filter j* are to be 
transferred by means of a platinum spatula 



* When the alumina or iron is in large proportion it 
carries down, unavoidably, some of the phosphoric acid 

G G 2 



452 PURE FERTILIZERS. 

and the spritz bottle to a small beaker, 
treated with pure hydrochloric acid, and 
digested on a hot sand-bath, until wholly 
dissolved. Aqueous solution of pure caustic 
potassa is then to be added in just sufficient 
excess to re-dissolve the alumina and phos- 
phate of alumina, w^hich it precipitates at 
first. Oxide of iron and phosphate of iron 
with phosphate of magnesia remain undis- 
solved, and are to be filtered off, thoroughly 
washed with hot water to remove every trace 
of potassa ; then dried, ignited, and weighed 
as filter k. The filtrate is l. 

The weight of the calcined filter k ex- 
presses the quantity of oxide of iron, phos- 
phate of iron, and phosphate of magnesia 
combined, which the raw material contains. 
To estimate them separately the calx is to be 
put into a beaker, and dissolved by the heat of 
a sand-bath in just sufficient hydrochloric 



belonging to lime. To prevent this source of error, I am 
now engaged in experiments by which the manufacturing 
processes, described at pp. 223 and 241, will be rendered 
precise analytical methods for separating phosphate of 
lime from its association with iron and aluminium com- 
pounds. 



CHEMICAL ANALYSIS. 453 

acid for the purpose. Aqua ammonia is next 
added, until the liquor blues red litmus 
paper, and then acetic acid in excess. Oxide 
of iron and phosphate of magnesia are held 
in solution, while phosphate of iron precipi- 
tates. This latter is to be filtered off, washed 
with hot water, dried and ignited, and 
weighed. The weight doubled, expresses the 
per cent, of ferric phosphate in the raw ma- 
terial. 

The composition of this ferric phosphate 
varies with the temperature of the liquor, its 
state of dilution, and the strength and pro- 
portion of the aqua ammoniae employed as 
precipitant. If the quantity is large, its con- 
tent of phosphoric acid must be determined 
by separation after the manner hereinafter 
described. 

8. Oxide of Iron. 

The filtrate from the phosphate of iron — 
containing the phosphate of magnesia and 
oxide of iron — is now to be diluted largely 
with boiling distilled water, treated with 
aqua ammoniae, y>/5/ to perfect neutralization, 
and filtered rapidly. The oxide of iron on 



454 PURE FERTILIZERS. 

the filter is to be washed with hot water, 
dried, ignited, and weighed. The weight 
doubled, expresses the per cent, of that ele- 
ment contained in the original raw material. 
It is indispensable to have the liquor dilute, 
hot and free from any excess of free ammo- 
nia, so as to prevent the oxide of iron carry- 
ing with it some of the phosphate of mag- 
nesia. 

9. Phosphate of Magnesia. 

The filtrate from the oxide of iron, just 
mentioned, is to be evaporated to a small 
volume upon the sand-bath, allowed to cool, 
then treated with aqua ammonite in excess, 
and set aside for ten to twelve hours. At 
the end of this time, the phosphate of mag- 
nesia will have crystallized out, and is to be 
filtered off", washed with ammoniated water, 
dried, ignited, and weighed. The process of 
ignition drives off the ammonia, and changes 
it into pyro-phosphate of magnesia (2MgO, 
PO5), every per cent, of which contains o'639 
of phosphoric acid. 



CHEMICAL ANALYSIS. 455 

10 and II. Phosphate of Ahtmina, and 
Alumina. 

The filtrate l, which was set aside pre- 
viously, is now to receive attention. It con- 
tains alumina and phosphate of alumina dis- 
solved in caustic potassa. This latter is to 
be fully neutralized by the addition of hydro- 
chloric acid, which first precipitates and 
then re-dissolves the aluminium compounds 
To throw them down wholly, it is next 
necessary to add carbonate of ammonia in 
excess. They are then filtered off, thoroughly 
washed with hot water, dried, ignited, and 
weighed. The weight expresses the Joint 
amount of alumina and phosphate of alumina 
in the raw material, and is to be noted in the 
record. 

The next step is to transfer the contents of 
the platinum crucible to a beaker glass ; add 
hydrochloric acid ; heat the solution on a 
sand-bath ; and dilute largely with water. 
This done, a large quantity of solution of 
citric acid is to be poured in ; and, finally, 
aqua ammoniae, with a slight excess of solu- 
tion of sulphate of magnesia containing chlo- 



456 PURE FERTILIZERS. 

ride of ammonium. The vessel is then 
covered, and left to repose in a cool place for 
twenty-four hours ; after which, its contents 
are to be filtered and washed with dilute 
ammonia water. 

The filter contains the phosphoric acid as 
phosphate of ammonia and magnesia, but 
mixed with greater or smaller traces of alu- 
mina and basic citrate of magnesia. To re- 
move these, the contents of the filter must be 
dissolved in hydrochloric acid, treated anew 
with a very small quantity of solution of 
citric acid, and re-precipitated by ammonia. 
After being washed with ammoniacal water, 
dried, and ignited, it is to be weighed as 
pyro-phosphate of magnesia (2MgO, PO5), 
every per cent, of which contains o"639 of 
phosphoric acid. As this portion of phos- 
phoric acid belongs, naturally, to alumina, it 
must be calculated to the latter, and written 
down in the table of results as phosphate of 
alumina. Every vo of phosphoric acid re- 
quires 0722 of alumina. 

The proportions of phosphoric acid and 
alumina thus determined being subtracted 
from the joint amount previously noted, give 



CHEMICAL ANALYSIS. 457 

the proportion of alumina in the mineral 
other than that which is combined with phos- 
phoric acid. 

As only fifty grains of raw material are 
taken for analysis, the figures of result must 
be doubled, in order to make them express 
the per cent. 



12. Alkaline Salts. 

The calx a from the organic matter and 
constitutional water determined in an earlier 
stage (page 439) of the process and then 
placed in reserve, is now to be treated for the 
separation of alkaline salts and fluoride of 
calcium. 

For this purpose it is boiled with an 
ounce of distilled water, allowed to cool, and 
then filtered and washed. The filter is m, 
and the filtrate is N. 

The filtrate n contains the alkaline salts 
(with some little sulphate of lime, probably), 
and is to be evaporated to dryness in a pla- 
tinum capsule on a hot sand bath. Its con- 
stant weight less that of the capsule is then 
taken and noted in the tabular result as 



458 PURE FERTILIZERS. 

alkaline salts. It must be doubled to ex- 
press the per cent. 

In rock guanos and mineral phosphates 
the alkaline salts consist, generally, of chlo- 
ride of sodium with sulphate of soda ; and 
their proportion is very small. But to de- 
termine whether any potassa is present, as 
well as to separate it in such case, the direc- 
tions hereinafter given on that point, for ana- 
lysis of superphosphates, must be followed. 

To determine whether any appreciable 
quantity of sulphate of lime remains with 
the alkaline salts, it is only necessary to add 
very dilute alcohol to the latter, after weigh- 
ing them, which will leave the former undis- 
solved. It can then be separated by filtra- 
tion, dried, ignited, and weighed. Its weight 
is to be deducted from the previous weight. 

13. Fluoride of Calciuni. 

If the presence of fluoride in the raw ma- 
terial was made evident by the corrosion of 
the glass cover to the beaker, in the earlier 
treatment for the separation of sand and 
silica, its quantity is now to be determined 
by fusing the contents of filter m in a plati- 



CHEMICAL ANALYSIS. 459 

num crucible with a mixture of six parts of 
carbonates of potassa and soda and two parts 
of silicic acid. This operation converts all 
the fluorine and phosphoric acid into soluble 
alkaline salts. The mass, w^hen cold, is to 
be treated with water, which renders liquid 
the soluble salts. The liquid is to be filtered 
off", and treated with solution of carbonate of 
ammonia which precipitates the silica. This 
latter is to be filtered off, and washed with a 
dilute solution of carbonate of ammonia. 
The liquor is now to be treated with hydro- 
chloric acid until it reddens blue litmus 
paper, and afterwards with a slight excess of 
solution of chloride of calcium. Fluoride of 
calcium, together with phosphate of lime, 
drop from the solution, and this precipitate 
is to be filtered off, washed with hot water, 
dried, ignited, and weighed. The calx is 
now to be placed in a platinum capsule, and 
heated with sulphuric acid until all the 
fluorine is expelled as hydrofluoric acid. 
Care must be observed not to let the heat be 
sufficiently high to volatilize any of the sul- 
phuric acid. The residue is then digested 
with hydrochloric acid to dissolve the phos- 



46o PURE FERTILIZERS. 

phate of lime, and afterwards with its own 
volume of alcohol to precipitate the lime as 
sulphate. After five or six hours' repose 
this latter is to be filtered off, washed with 
alcohol, dried and weighed. Every ro of 
dry sulphate of lime contains 0'4ii7 of lime 
or oxide of calcium. 

The filtrate from the sulphate of lime is to 
be evaporated on a sand bath, for the vola- 
tilization of the alcohol, then treated with a 
mixture of sulphate of magnesia and chlo- 
ride of ammonium, and finally with an ex- 
cess of aqua ammoniae. After six or eight 
hours' repose the phosphoric acid will have 
separated, wholly, as phosphate of magnesia 
and ammonia. This latter is to be filtered 
off, washed with hot water, dried, ignited, 
and weighed as pyrophosphate of mag- 
nesia. Every i"o of this latter salt of mag- 
nesia contains 0'639 of phosphoric acid. 

The total of lime and phosphoric acid hav- 
ing now been determined, so much of the 
former must be apportioned, by calculation, 
to the latter as is necessary to make tri-phos- 
phate of lime, or, in other w^ords, i'i66 of 
lime to every ro of phosphoric acid. The 



'- " ~^' — ' 



„l L. 



L...^ 



WicentBr 



TriibnerS: C?.6C.PaieiTL0sterRcw. 



MORrir on ihe Manulacluir nfFertili^'r^ 




SpecialVy dEsigiied for K Morfiis Work ai Feniliza- 



Triibner k C?.6C.Pajei7io5tprRDW. 



CHEMICAL ANALYSIS. 461 

residue of lime belongs to the fluorine which 
is expelled, and every vo of CaO makes or is 
equivalent to i'40 fluoride of calcium (CaFl). 
The figures obtained must be doubled to ex- 
press the per centage. 

14. Carbonate of Lime. 

If on the addition of acid to the raw ma- 
terial, there is any effervescence, this action 
denotes the presence of carbonate of lime. 
To determine the amount, a separate or new 
portion of fifty grains of the raw material in 
fine powder must be taken, and treated in a 
special apparatus shown by fig. 20, which is 
drawn one-third smaller than the natural 
size. 

It consists of a very light glass flask a, as 
the vessel for receiving the powder ; a glass 
pipette b, and a drying tube c, containing 
chloride of calcium, both of which latter con- 
nect with the former by means of a tightly 
adjusted cork h. The pipette is to be filled 
with either sulphuric acid or a very strong 
solution of tartaric acid, by dipping the 
lower end into the liquor and drawing the 
latter up into the bulb by placing the 



462 



PURE FERTILIZERS. 



mouth at the upper end. This portion is 
then fitted with a piece of india-rubber tube 
and one of Mohr's clamps d, shown enlarged 
by fig. f. The clamp and india-rubber tube 
serve to exclude or admit air into the flask 



^ 5 





Fie 20. 



as may be required ; it being only necessary 
to press upon the keys g g with the fingers 
when it is desired to open the tube, and to 
remove them when it is to be closed. When 
the weighed portion of powder has been put 
into the flask, the latter is to be closed tightly 



CHEMICAL ANALYSIS. 463 

with the cork stopper, and the whole appara- 
tus and contents carefully weighed on the 
fine balance. This weight having been noted 
in the record, the acid is then made to flow 
from the pipette in drops, by pressing the 
keys of the clamp at short intervals. 

Carbonic acid having a much feebler che- 
mical affinity than either sulphuric or tar- 
taric acids, is displaced by either of these 
latter from its combinations, and driven off 
in the form of gas, as indicated by the effer- 
vescence which takes place ; and if in its 
escape it should be involved with any me- 
chanically mixed water, this will be arrested 
by the chloride of calcium as it passes 
through the drying tube, — that salt being a 
hygroscopic substance. Nothing but car- 
bonic acid escapes ; and after all the acid 
has been allowed to fall upon the powder, 
and effervescence has ceased for some ten or 
twenty minutes, the lips are to be applied to 
an india-rubber tube temporarily drawn over 
the end of the exit tube e, and the residual 
traces of gas drawn out of the apparatus 
by suction. This india-rubber tube being 
then removed, the apparatus is to be weighed 



464 PURE FERTILIZERS. 

again. The difference between this second 
and previous weight shows a loss which ex- 
presses the amount of carbonic acid in the 
raw material. The carbonic acid is to be 
calculated to lime (CaO) and in the propor- 
tion of I '27 lime to every i.o of carbonic 
acid. The equivalents of lime belonging 
severally to the fluorine and the carbonic 
and phosphoric acids being now added to- 
gether and deducted from the total of lime 
previously estimated, may leave a remainder. 
In that case the remainder is to be set down 
in the table as Lime with organic and silicic 
acids, and probably also with alnmina. 

The results are to be arranged in the order 
shown by the following table. 

Recapitulation . 



Moisture 


- 


- say 2 00 


Organic matters - 


- 


- n 2-50 


Sand and silica - 


- 


- » 3 '00 


Fluoride of calcium 


- 


- M 4'00 


Sulphate of lime 


- 


- » S'oo 


Carbonate of lime 


- 


- » 7'oo 


Lime (with organic and sii 


licic acids) - 


„ 2-00 


Bone-phosphate of lime 


- ■ 


- „ 5800 


Bone-phosphate of magnesia 


- „ 3-50 


Phosphate of alumina 


- 


- „ 500 



CHEMICAL ANALYSIS. 465 



say 3-00 


„ 2-00 


„ I -oo 


„ 2-00 


lOO'OO 



Phosphate of iron 
Oxide of aluminium 
Oxide of iron 
Alkaline salts 

Total 



The phosphoric acid is thus shown in its 
individual combinations and not totalized as 
tri-phosphate of lime, according to the mere- 
tricious style of ^^ commerciar chemistry. 

FORMULA FOR THE CHEMICAL ANALYSIS OF 
MINERAL PHOSPHATES OF ALUMINA AND 
IRON. 

In the preceding formula, instructions have 
been given for the separation of the alumi- 
nium and iron compounds from those of lime, 
because there are very few mineral phos- 
phates of lime which do not contain more or 
less of those compounds. 

On the other hand, there are certain 
mineral phosphates of alumina and iron 
wholly free from lime associates. To ana- 
lyze these, therefore, is a simple process, it 
being necessary to follow only those parts of 

the formula already explained, which apply 

II II 



466 PURE FERTILIZERS. 

to their special components. Taking " Re- 
doiida Guano' as a typical specimen, these 
components are, in their proper order of 
arrangement, generally as follows : — 

Water _ . _ - 

Organic matter - _ _ 

Sand and silica . - - 

Sulphate of lime _ . _ 
Phosphate of alumina 

Phosphate of iron . _ _ 

Oxide of aluminium . - - 

Oxide of iron _ _ _ 



Total 



a. Water. 



An average sample of about four ounces 
having been selected, is to be reduced, wholly, 
to fine powder in a polished iron or steel 
mortar. Fifty grains are then to be heated 
in a platinum crucible on a very hot sand 
bath, until the weight becomes constant. 
The loss of weight thus produced expresses, 
when doubled, the per cent, of water in the 
mineral, 

b. Organic Matter. 
The residue is further heated, but over a 



CHEMICAL ANALYSIS. ^67 

gas flame, to redness until it ceases to lose 
weight. The difference between its constant 
weight after the heating, and its previous 
weight, expresses, when doubled, the per 
cent, of organic matter in the mineral. 

c. Sand and Silica. 

The calx is then to be emptied from the 
crucible into a small beaker glass, drenched 
with hydrochloric acid, and heated on a sand 
bath. After an hour, sulphuric acid is to be 
added very cautiously, for otherwise too 
violent action may ensue, and cause the 
ejection of some of the contents of the glass. 
Enough acid must be added to thin the 
mass to fluidity. After which, digestion is 
to be continued until all the soluble matter 
is taken up, as will be indicated by the 
liquor having assumed a thick syrupy con- 
sistence without solid residue at the bottom. 
It is then evaporated to dryness on the sand 
bath, treated with a few drops of hydro- 
chloric acid and sulphuric acid, and again 
digested for ten minutes. Hot water being 
then added to make a thin dilution, the 
whole is to be stirred and filtered. The 

H II 2 



468 PURE FERTILIZERS. 

washed, dried, ignited, and weighed filter 
represents the sand and silica. 

d. Sulphate of Lime. 

The filtrate may contain, in rare instances, 
some small portion of sulphate of lime ; 
therefore its volume must be reduced two- 
thirds by evaporation on a sand bath ; after 
which a double volume of alcohol is to be 
added. If it contains sulphate of lime, this 
salt will precipitate, and must be filtered off, 
washed, dried, ignited, and weighed. 

e. Alumina aud PJiosphate of Alumina. 

The filtrate contains alumina and oxide of 
iron together with their phosphates, and 
must be evaporated to expel alcohol. Solu- 
tion of caustic potassa is then added in ex- 
cess, so as to hold in solution the aluminium 
compounds while it precipitates those of 
iron. These latter are to be filtered off, 
washed with hot water, dried, ignited, 
weighed and set aside as a. 

The filtrate is now to be treated for the 
separation and estimation of its alumina, 



CHEMICAL ANALYSIS. 469 



and phosphate of alumina, precisely in the 
manner described, for filter k, in paragraphs 
10 and 1 1 of the preceding formula. 

f. Oxide of Iron and Phosphate of Iron. 

The calx a contains only these two com- 
ponents, and it is to be digested in a beaker 
glass with sufficient hydrochloric acid to 
effect its solution. The further treatment is 
then precisely similar to that described in 
paragraphs 7 and 8 of the preceding formula. 

FORMULA FOR THE CHEMICAL ANALYSIS OF 
COMMERCIAL SUPERPHOSPHATE OF LIME ; 
AND COMPOUND FERTILIZERS. 

The commercial superphosphates of lime 
vary in their composition, according to the 
skill and integrity which may have been 
practised in the manufacture of them. Che- 
mical analysis is the only mode of deter- 
mining their value previous to use, and 
should be made as follows. 

A. Water. 
Average the sample- fairly, weigh out a 
portion of 50 grains in a counterpoised 



470 PURE FERTILIZERS. 

watch-glass, and dry over a sand-bath at 
200° to 212° Fahrenheit until weight ceases 
to be lost. The loss which the constant 
weight indicates, will, when doubled, express 
the per cent, of accidental water in the 
sample. 

B. Bi-Phosphate of Lime. 

A fresh portion of 50 grains is to be tri- 
turated in a porcelain mortar with distilled 
water, and poured into a small glass funnel 
loosely plugged in its stem with cotton-wool. 
When the liquor has run through into a 
beaker glass beneath, a fresh relay of cold 
water is poured on and allowed to infiltrate 
through as before. In this way the infiltra- 
tion is further repeated thrice with cold, and 
subsequently several times with boiling 
water or until all the soluble matter has been 
displaced or washed out. This will be 
shown so soon as the filtrate, running 
through, no longer leaves a decided tache, 
when a drop has been evaporated to dryness 
upon a platinum spatula. The use of cold 
water insures the extraction of any soluble 
aluminium phosphate that may be present ; 



CHEMICAL ANALYSIS. 471 

for, according to Warrington, hot water 
would coagulate and keep it back. 

The filter is a, and must be kept in reserve 
as the insoluble portion. The filtrate b con- 
tains all the soluble phosphate, together with 
some little sulphate of lime, and any sul- 
phates of alumina and iron that may have 
been in the sample. 

It is to be reduced, by evaporation on a 
sand-bath, to a small volume, and treated 
with alcohol for the precipitation of the sul- 
phate of lime. This latter is then to be fil- 
tered off, washed, and added to the reserved 
filter A, containing the portion of the sample 
insoluble in water. 

Lime-water is now to be added to the 
filtrate c, a little at a time, until precipita- 
tion or cloudiness ceases to be formed. 
Great care must be observed to restrict the 
lime as nearly as possible to the exact quan- 
tity, and this is nice manipulation. The 
better way will be to keep back about one- 
eighth of the liquid, so that this reserve may 
be at hand for a readjustment of the neu- 
trality, in case of too much lime-water having 
been added to the first portion. Very thin 



472 PURE FERTILIZERS. 

milk of lime, strained through a bolting or 
other fine cloth, may be used instead of lime- 
water, and with the advantage of producing 
less volume of liquid ; but, in this case, the 
manipulation must be more expert, so as to 
prevent the addition of any excess of lime. 

This treatment throws down all the phos- 
phoric acid as phosphate of lime, with any 
alumina and oxide of iron, which may have 
been present in the solution. The precipi- 
tate is to be filtered off, washed, and noted 
as D. The filtrate is e. 

The filter d is to be transferred to a beaker 
glass, and dissolved in just sufficient hy- 
drochloric acid, by the heat of the sand- 
bath. A small quantity of water is added, 
and afterwards a double volume of alcohol. 
Finally, sulphuric acid is to be added, a 
drop at a time, until all the lime has precipi- 
tated as sulphate. The sulphate of lime, 
thus formed, is then filtered off, washed, and 
thrown away. The filtrate contains all the 
phosphoric acid with the alumina and iron. 
It is to be evaporated on a sand-bath for the 
expulsion of alcohol, and then treated with 
ammonia to throw down the alumina and 



CHEMICAL ANALYSIS. 473 

iron. Filter, wash well with hot water, and 
set aside as filter f, containing iron and alu- 
mina. 

The filtrate now holds only phosphoric 
acid, and is to be treated precisely as directed 
in paragraph 6 of the first formula. Every 
ro of phosphoric acid (PO5) is equivalent to, 
or makes, v6^ of biphosphate of lime (CaO, 
2HO, PO5). 

If it is only desired to estimate the amount 
of soluble bi-phosphate which the sample 
may contain, the analysis here ends. But 
as this component is often associated in arti- 
ficial mixtures, with precipitated phosphate, 
bone-phosphate, ammoniacal and alkaline 
salts, it is proper that the formula should 
comprise instructions for a thorough analy- 
sis, in the progress of which, any and every 
probable component may be detected and 
estimated. 

c. Alumina and Iron. 

Therefore, the filter f is to be ignited and 
weighed. The weight having been recorded, 
the calx is then dissolved in hydrochloric 
acid by the aid of the sand-bath, and treated 



474 PURE FERTILIZERS. 

with citric acid, as directed in paragraphs 7 
to II, for the separation of any phosphoric 
acid which it may contain. The weight of 
the phosphoric acid deducted from the pre- 
vious total weight of the calx leaves the 
weight of- the aluminium and iron oxides. 
Both weights must be doubled to express 
the per cent, relations, and are to be recorded 
in the table among the soluble constituents 
of the sample. 

D. Chloride of AuinwJiiimi. 

The filtrate e having been poured into a 
platinum capsule of known weight, is to 
be evaporated to dryness upon or over a 
sand-bath at a temperature not exceeding 
212^ Fahrenheit. When it ceases to lose 
weight, its constant weight is to be noted. 
The crucible and contents are then to be 
heated over a gas flame, much below redness, 
until vapours cease to be given off. Chlo- 
ride of ammonium, if any is present, thus 
volatilizes ; and the capsule being now 
weighed will show a loss on its previous 
weight. This loss, doubled, expresses the per 
cent, of chloride of ammonium in the sample. 



^ CHEMICAL ANALYSIS. 475 

EE. The residue is now dissolved in water, 
diluted to a given number of cubic centi- 
metres, and then divided into two equal por- 
tions, G and H. It should be remarked here, 
that the solution may contain both chlorides 
and sulphates of the alkalies, together with 
sulphate of ammonia. 

F. Sulphate of Ammonia. 

The portion g must be treated with chlo- 
ride of barium in a careful manner, so as to 
avoid an excess. The precipitate is then to 
be filtered off, washed with hot water, dried, 
ignited, and weighed. Every i 'o of this cal- 
cined filter of sulphate of baryta (BaO, SO3) 
contains 0*34335 of sulphuric acid, and this 
acid is to be apportioned, as will be explained 
hereafter. 

The sulphates having been converted thus 
into chlorides, are to be evaporated to dry- 
ness, as before, and the constant weight 
noted. Afterwards, the mass is to be heated, 
as in the previous instance, to expel any 
chloride of ammonium that may have been 
formed from sulphate. It must be weighed, 
therefore, again, to determine the amount of 



476 PURE FERTILIZERS. 

loss, if any. Every ro of this loss, being 
chloride of ammonium, represents r257 of 
sulphate of ammonia. 

G. Potassium Chloride. 

The residue is then dissolved in water, and 
a little carbonate of soda added to precipi- 
tate any excess of baryta salt that may have 
been added. The liquor is then filtered and 
washed. The filter is thrown away ; but the 
filtrate is to be reduced, by evaporation, to a 
small volume, treated with a strong solution 
of neutral chloride of platinum in slight 
excess, and evaporated in a porcelain capsule 
nearly to dryness over a water-bath. A mix- 
ture of alcohol, of 80 per cent, strength, and 
ether, is then added, and the whole left to 
digest for some fifteen to thirty minutes. 
The double salt of chloride of platinum and 
potassium is thus rendered wholly insoluble, 
and must be filtered off upon a counterpoised 
filter, dried, and weighed. Every ro of this 
salt (KCl, Pt, CI2) contains 0-30507 of chlo- 
ride of potassium, and every ro of this latter 
salt is equivalent to r 166 of sulphate of 
potassa, or o'523 of potassium deducted from 



CHEMICAL ANALYSIS. 477 

the previous weight (paragraph f) gives the 
amount of chloride of sodium in the filtrate. 

To determine whether any of the potassium 
or sodium may have existed originally as 
chloride, it is first necessary to test the H 
portion of the liquor previously noted, with 
nitrate of silver. If any precipitate falls, it 
must be filtered off upon a counterpoised 
paper, washed with hot water, dried, and 
weighed. Every ro of the chloride of silver 
thus precipitated contains '2472 of chlorine, 
and every i*o of chlorine is equivalent to 
2* 10 of chloride of potassium. The chlorine 
is allotted to potassium, first, because this 
latter is a stronger base than sodium, though 
it is possible a part of it may belong really 
to the latter, if it were known how to deter- 
mine that point and portion under existing 
circumstances. 

H. Sulphate of Potassa. 

If there should be more of potassium than 
the chlorine requires, this residue was origin- 
ally in the form of sulphate. Therefore, as 
much of sulphuric acid as it may require to 
convert it into KO, SO3, must be deducted 



478 PURE FERTILIZERS. 

from the total baryta product of the portion 
of liquor G. Every vo of potassium needs 
1*23 of oxygen and sulphuric acid jointly, to 
convert it into sulphate of potassa. 

J. Chloride of Sodium. 

If the amount of chlorine obtained should 
be more than sufficient for all the potassium, 
then the excess is to be calculated to sodium 
as chloride of sodium. Every vo of chlorine 
(CI) is equivalent to 0-6486 of sodium (Na), 
or I '648 of chloride of sodium (NaCl). 
This proportion of chloride of sodium is to 
be deducted from the total amount of soda 
salts, previously determined. 

K. StilpJiate of Soda. 

The remainder of the sulphuric acid should 
exactly or closely fit the residual amount of 
chloride of sodium, already determined, as 
sulphate of soda is most probably the form 
in which it originally existed in the sample. 
Every ro of chloride of sodium is equivalent 
to 0*684 of sulphuric acid, and every ro of 
this latter makes 1782 of sulphate of soda. 

As only 50 grains of the sample were 



CHEMICAL ANALYSIS. 479 

taken for the analysis, and this portion was 
divided into moieties, for the estimation of 
the chloride of potassium and sulphates of 
potassa, soda, and ammonia, the figure results 
for these latter must be multiplied by four, 
in order to express the per cent, relations. 

L. Nitrate of Soda. 

Though this salt is not comprised in any 
of my products, it may be a component of 
other fertilizers, as it is now largely used in 
their manufacture ; and, therefore, a proper 
formula for chemical analysis should com- 
prise instructions for detecting and esti- 
mating it. 

Its presence may be determined by leach- 
ing a sample of the fertilizer with water, 
filtering, and evaporating a few drops of the 
filtrate to dryness in a platinum crucible. If 
now, on adding to the dry mass a few drops 
of sulphuric acid and heating, there should be 
an appearance or smell of orange-red nitrous 
fumes, they are proof of the presence of a 
nitrate, which is most generally nitrate of soda. 

In that case, then, a fresh portion of 50 
grains of the original sample is to be di- 



480 PURE FERTILIZERS. 

gested in a beaker glass and on a hot sand- 
bath with distilled water. All the soluble 
matter of the sample will be thus taken up ; 
and the whole is to be filtered and washed. 
The filter, being foreign to this determina- 
tion, is to be thrown away. The filtrate is to 
be treated with thin and smooth milk of 
lime until this latter ceases to throw down a 
precipitate. Filter and wash. The filter 
containing alumina, oxide of iron, and phos- 
phate of lime, is to be thrown away ; as all 
of these matters have been estimated accord- 
ing to the instructions in previous para- 
graphs. 

There remains nothing in the filtrate but 
alkaline salts and nitrate of soda, with some 
sulphate of lime. It is to be evaporated 
to dryness and constant weight, in a plati- 
num crucible the weight of which has 
been previously noted, and there is then 
to be added to the saline mass some pure 
powdered silica. The silica must be pre- 
viously heated, to insure perfect dryness, 
and its proportion must be four to six times 
the supposed weight of the nitrate of soda. 
The mixture of the two having been made 



MOEFir 



PI..4 ,. •) 



ale _'/ 



Elevation 



MOB FIT on the Manufhetnrv of Fertilisers. 



Elevator and Digestion Vats_ End Elevati 



ON. 




CHEMICAL ANALYSIS. 481 

intimate by stirring with a glass rod, the 
whole is then carefully weighed and its exact 
weight recorded. The crucible being then 
covered, is to be heated for one half hour 
over a gas flame to a redness which is so low 
as to be only barely visible in the day time. 
At this temperature the nitric acid of the 
soda (or potassa) will pass off, while any alka- 
line chlorides or sulphate that may be pre- 
sent remains undecomposed. The crucible 
and contents being weighed again, when 
cool, will show a loss which represents the 
amount of nitric acid expelled. Every ro of 
this nitric acid (NO5) is equivalent to o"5796 
of soda (NaO), and represents i'5796 of 
nitrate of soda. The result is to be multi- 
plied, of course, by two, in order to make 
it express the per cent, relations. 

The portion of the fertilizer soluble in water 
having been thoroughly analyzed, the next 
operations must be with the insoluble part 
which was placed in reserve as filter a, at an 
early stage of the examination. The quali- 
tative and quantitative steps are one and the 
same in this formula, — that is, they proceed 

together. 

1 1 



482 PURE FERTILIZERS. 

M. Precipitated Phosphate of Lime. 

The filter a having been perfectly dried, 
its contents are weighed and then transferred 
to a beaker glass. . Pure concentrated acetic 
acid of specific gravity i'05 is next to be 
added, and the whole left to digest in the 
cold for half an hour. By this treatment, 
carbonate and precipitated phosphate of lime 
are dissolved, while the bone-phosphate of 
the natural mineral remains nearly un- 
touched, on account of its dense physical 
structure. The whole is then filtered and 
washed ; the filter being j and the filtrate k. 

The filtrate k is treated with a slight ex- 
cess of aqua ammonise filtered and washed. 
The filter is then dried, ignited, and weighed. 
The weight, multiplied by two, expresses the 
percentage of precipitated phosphate of lime, 
which may contain, also, some possible trace 
of free carbonate of lime. 

N. Carbonate of Lime. 

The filtrate from the preceding filter is to 
be treated with oxalate of ammonia, until a 
precipitate or cloudiness ceases to form. The 



CHEMICAL ANALYSIS. 483 

oxalate of lime is then to be filtered off, 
washed, dried, ignited, and weighed. As 
oxalate of lime changes into carbonate by 
ignition, the weight, doubled, represents the 
per cent, of carbonate of lime in the sample. 

o. Organic Matter. 

The filter j having been thoroughly dried 
at 212^^ Fahrenheit, its contents are then 
weighed and afterwards calcined in a plati- 
num crucible. 

The loss of weight thus produced by igni- 
tion represents the amount of organic matter 
in the sample. 

p. Sand and Silica. 

The remaining calx is now to be treated 
with hydrochloric acid, and carried through 
the operations explained at length in para- 
graphs 3, 4, 6, 7, 8, 9, 10, II, and 13 of the 
first formula of this chapter. In this manner, 
each and every one of its probable constitu- 
ents will thus be detected and estimated. 

The formula just given is made compre- 
hensive, so that it may apply in the first part 
to commercial superphosphates of lime, and 



1 1 2 



484 PURE FERTILIZERS. 

in its entireness to any and every fertilizing 
mixture of artificial manufacture, however 
complex. 

The constituents having been separated 
and quantitatively determined, should be 
formulated according to the following ar- 
rangement. 

Recapitulatioit. 

Soluble bi-phosphate of lime - - - 
Precipitated phosphate of lime 
Bone- or tri-phosphate of lime 

Bone-phosphate of magnesia - - _ 

Chloride of ammonium _ _ _ 

Chloride of potassium - _ _ 

Chloride of sodium - - - - 

Sulphate of ammonia _ _ _ 

Sulphate of potassa _ _ _ 

Sulphate of soda - - - . 

Nitrate of soda . _ _ - 

Sulphate of alumina _ _ _ 

Sulphate of iron - _ _ _ 

Phosphate of alumina _ _ _ 

Carbonate of lime - - - - 
Lime, with organic and sihcic acids and alumina - 

Fluoride of calcium - . _ 

Alumina - - - _ - 

Oxide of iron - - _ _ 

Sand and silica - - _ _ 
Organic matter - " - 

Water - - . - . 

Total 



CHAPTER XXIV. 

ON THE COMMERCIAL VALUATION OF CRUDE 
AND REFINED FERTILIZING MATERIALS. 

In computing the value of a fertilizing mate- 
rial there should be a close adjustment of its 
commercial and agricultural relations. 

The prime elements of a profitable ferti- 
lizer are nitrogen, phosphate of lime, and 
potassa. To determine, however, the com- 
mercial and agricultural worth of a fertilizing 
material, it is necessary to ascertain its pre- 
cise composition and nature by a fidl chemi- 
cal analysis. The questioning, in this re- 
spect, must be both scientific and conscien- 
tious ; for no mere partial investigation will 
serve the importance of the subject. Not 
only must it be learned what constituents 
are present, but in which forms they exist 
and with what associates they may be accom- 
panied. 



486 PURE FERTILIZERS. 

In a general sense, the form or state regu- 
lates the agricultural value of a fertilizing 
element ; but the character of its associates 
affects, more or less, the computation. 

AmmoJtia. 

Thus, as to azotized matters, those which 
contain their nitrogen in the form of ammo- 
niacal salts are the most active; while others, 
on the contrary, like woollen waste, horn, and 
leather clippings, which contain it in a com- 
paratively dormant or quiescent state, acquire 
chemical or fertilizing momentum, so to 
speak, only by the aid of time and decompo- 
sition. These influences add to the first 
cost and change the classification or money 
rank of the material. Here, moreover, sub- 
stances of this kind which are most prone to 
decomposition, are worth more, proportion- 
ally, than others of their class. Intermediate 
between these two, is a third form existing 
as urea, urate, and phosphate, in farm-yard 
manure, bird guanos, human excrements, 
and kindred substances ; which, though not 
active or dormant, are more potential than 
cither. I use this term, potential, to desig- 



COMMERCIAL VALUATION. 487 

nate a great sensitiveness to the assimilating 
powers of the growing crop, whereby the 
plant is enabled to take up its nutriment 
in condition and quantity as may be wanted 
to produce the highest degree of progressive 
development with the least possible expendi- 
ture of time and fertilizer. This form of 
nitrogen being the most valuable, in every 
sense, should constitute the standard of esti- 
mation ; but, unfortunately, the supply of it 
is too limited, at present, to justify that posi- 
tion for it. Later, when its source becomes 
amply extended by the separation of the 
organic matter from the phosphate-sewage 
precipitate, as suggested at pp. 397 to 405, it 
may assume the controlling position in the 
appreciation of nitrogenous substances. 

In the meantime, there remain only the 
ammonium chloride and sulphate as a solid 
standard of comparison. The abundant and 
regular production of crude ammonia liquors 
in the coal-gas and bone-black works, render 
those salts, already, the most prominent part 
of the ammonia supply ; and this source not 
only assumes a progressive increase, but is 
becoming widened by lateral feeders from the 



488 PURE FERTILIZERS. 

utilization of woollen wastes for the purpose. 
Not Jong hence, it will expand into yet 
larger proportions, when the excrements of 
mankind are turned into this account or cur- 
rent, after the manner which I have noted at 
p. 47 ; or the air is exploited for the purpose. 

With this explanation, therefore, ammonia 
must be set down at its average value in 
ammonia salts, which is £^c)0 per ton or 
1 8s. per unit ; the present market price 
of ammonium chloride being ;^30 per ton, 
while that of sulphate of ammonia is £^22 
per ton. Materials containing nitrogen in 
a dormant or quiescent state are to be 
rated at a figure so much less as will cover 
the manufacturing expense of converting 
that nitrogen into its equivalent of ammo- 
nia salt, with twenty per cent, superadded for 
profit and contingencies. 

The unit refers to the ton of 2240 pounds, 
and is used in accordance with the prevailing 
British custom, which requires that the com- 
putation shall be made by unit rather than 
by per cent. 

Every per cent, of any constituent of a 
material, when multiplied by twenty, becomes 



COMMERCIAL VALUATION. 489 

a unit. Thus, for example, if a material 
should contain seventeen per cent, of ammo- 
nia or the equivalent in nitrogen, with the 
cost of conversion added, it is said to have 
17 units of ammonia, although the latter 
represents in fact 380 pounds of ammonia in 
the ton of the material. 

The method of calculating by per cent, is, 
however, the more rational one, as it gives 
expression to the actual quantity or propor- 
tion of the valuable constituent of a raw 
material. On the other hand, the unit 
method excludes from the computation 240 
pounds of the ton, as a concession to trade 
influence. 

Phosphates of Lime. 

Bone-ash or animal phosphate of lime is 
the typical expression of this material ; and 
pure apatite and phosphorite may be taken 
as the best representatives of its mineral 
condition. 

Animal Phosphate of Lime. 

Bone-ash has a peculiarly sensitive tem- 
perament in its chemical relations, and is 



490 PURE FERTILIZERS. 

well suited for immediate potential effect 
upon soils. It is more uniform in composi- 
tion than any other kindred material, and 
contains a higher average of actual phosphate 
of lime. Moreover, in this material there is 
only an inconsiderable proportion, compara- 
tively, of profligate matters associated with 
the phosphate of lime constituent. 

On these accounts it holds a commercial 
and agricultural position apart from other 
kinds of its class. The laws of supply and 
demand regulate, therefore, its market price, 
which is at present £^(i ' 15 to £^^ per ton, or 
2s. per unit. This value refers to ash con- 
taining 70 per cent, of tri-phosphate of lime, 
that being the usual strength. 

Bone-black and bone-dust are to be esti- 
mated by the above standard, for similar 
reasons, but according to the proportion of 
tri-phosphate of lime which they may con- 
tain. At the same time, their content of 
nitrogenous matter must be taken into con- 
sideration. This is potential in character, 
and its money value is to be computed, as 
explained already under ammonia, and added 
to that of the phosphate constituent. 



COMMERCIAL VALUATION. 491 

Miiiei^al Phosphate of Lime. 

The mineral phosphates of lime, even of 
the highest grade, have a dense structure and 
rocky nature, which give them a chemical, as 
well as physical temperament, quite distinct 
from that of bones, bone-ash, or bone-black. 
Moreover, a greater or lesser quantity of the 
phosphoric acid which they may contain is 
combined, almost invariably, with iron and 
alumina ; whereas, the animal phosphate of 
lime holds that acid wholly as tri-phosphate 
of lime. The presence, too, of foreign asso- 
ciates with the lime phosphate element is 
an important modifying influence in deter- 
mining the commercial value of a mineral 
phosphate. 

I restrict my remarks to the commercial 
value because mineral phosphates in their 
natural crude state are very slow indeed as 
direct agricultural agents. The foreign mat- 
ters which they contain exert a cementing 
action upon the valuable phosphate of lime 
constituent, and thus impart to this latter an 
inertia which militates against its fertilizing 
activity. Though vegetation will draw its 



492 PURE FERTILIZERS. 

nourishment from the most available source, 
however difficult, its vigour of structure and 
productive capacity will be more or less 
feeble if the nutriment should be either de- 
ficient in quantity or obstinate to the atmo- 
spheric and solvent influences of the soil. 
Plants thrive best when their food is present 
in assimilable or potential forms ; and, con- 
sequently, time and money are both wasted 
in sowing fertilizers which may be tough in 
nature or sluggish in action. 

The phosphate of lime constituent re- 
quires, therefore, to be separated from its 
disadvantageous association of foreign mat- 
ters ; and this involves the expense of 
chemical agents, labour, time, etc. 

The foreign matters, to say the least, are 
unprofitable diluents of the phosphate of lime 
constituent. Indeed, their presence in mine- 
ral phosphates is an injurious influence of 
important degree. Apart from their cement- 
ing action, they have the disadvantage of 
importing into the products a humid pro- 
perty and a large degree of dilution, without 
any compensating advantage whatever, when 
the crude mineral is treated with acid for 



COMMERCIAL VALUATION. 493 

conversion into pure phosphates of lime. 
They not only waste acid in this manner, but 
really are barriers to its free action upon the 
phosphate of lime constituent, as the latter 
remains intact until the associate matters 
have been overcome chemically. 

As promoters of waste and excessive dilu- 
tion, I term these foreign matters profligate 
elements or associates ; and they consist of 
fluoride of calcium, carbonate of lime, organ- 
ate and silicate of lime, oxide of iron and 
alumina, in first degree ; and of sand, silica, 
and organic matter, in secondary importance. 

Pure tri-phosphate of lime, divested of all 
associates passive in themselves, or which 
might paralyze its fertilizing action, is, there- 
fore, the only sound basis for computing 
the value of a crude phosphate of lime. 
There is no such standard in Nature, practi- 
cally considered ; but if one should be found, 
it would be worth double the market value of 
a mineral containing only 50 per cent, of tri- 
phosphate of lime, plus the cost of the acid, 
labour, and manufacturing expense which 
the residual moiety of profligate elements 
would entail in the conversion of two tons of 



494 PURE FERTILIZERS. 

such crude material into the one ton of pure 
phosphate. 

As the per cent, of phosphate of lime falls, 
that of the profligate associates rises ; and 
hence the convenience and expense of re- 
fining a crude mineral are dependent upon 
the prevailing circumstances in this respect ; 
and, correspondingly, the value will progress 
downwards or upwards in regular arithmeti- 
cal proportion. 

The medium grades of mineral constitute 
the major part of the crude phosphate re- 
sources, and, being unsuited for fertilization 
until they have been chemically prepared, it 
follows that the basis for computation must 
be selected from them. And, as seems to 
me most justifiable, I take one containing 45 
per cent, of actual tri-phosphate of lime, the 
present market value of which is tenpence 
one farthing per unit, or thirty-eight shillings 
and sixpence per ton. This kind of mineral 
phosphate of lime has expression in the 
Wicken and Calais Coprolites, and the best 
quality of ''South Carolina Phosphate'. 

Taking, then, a crude mineral of 45 per 
cent, of lime phosphate strength, at its pre- 



COMMERCIAL VALUATION. 495 

sent market value of £\ : 5 for 2*20 tons, the 
only datum that is needed to form a table of 
the money value of different grades of raw 
phosphate is the mere expense for chemicals, 
labour, fuel, etc., which would be consumed 
for refining that quantity of crude mineral into 
its equivalent of ro ton of pure or standard 
phosphate of lime. This would be £^ : 15, 
according to my experience, and must be dis- 
tributed, therefore, through all the degrees 
from 45 to 100 of the scale, in order to ex- 
press a correct graduation of the value. 

There are, consequently, fifty-five degrees 
which are to share the amount which is to be 
apportioned ; and, as the ratio of phosphate 
may rise degree by degree, in the raw mine- 
ral, each degree will hold not only its original 
value of tenpence farthing per unit, but an 
additional one acquired by the saving of the 
refining expense which, otherwise, would be 
involved by displacing its equivalent of pro- 
fligate elements. 

Starting, therefore, at tenpence farthing 
per unit for a raw mineral containing 45 
per cent, of actual tri-phosphate of lime, 
there must be a progressive advance of one 



496 PURE FERTILIZERS. 

farthing for each degree, so that when the 
natural quality of the mineral may have risen 
to purity, as in some specimens of apatite, it 
will represent a value of two shillings per 
unit. 

In like manner, the scale may be carried 
downwards by diminishing the valuation, 
progressively, a farthing for each degree of 
actual phosphate of lime strength ; but, for 
manufacturing purpose, the mineral should 
not have less than twenty-four degrees, in that 
respect. In other words, mineral phosphates 
cease to be profitable when they contain less 
than 24 per cent, of actual phosphate of lime. 

The following table is founded upon this 
basis, and refers to the actual per cent, or 
degree oi phosphate of lime, because it is my 
habit always to distinguish that portion of 
phosphoric acid thus united from that which 
may be combined with the oxides of iron and 
aluminium that are present, and for the 
simple reason that the latter is, agriculturally, 
much inferior in value to the former, and 
should be estimated separately. 

This explanation is rendered necessary by 
the fact that analyses of mineral phosphates 



COMMERCIAL VALUATION. 40)7 

are made often in a '' commerciar style most 
discreditable to science and the chemical 
profession. Not only are incongruous con- 
stituents grouped together, in the report, 
under one head ; but the total of phosphoric 
acid is expressed most frequently by its eqid- 
valent in tri-phosphate of lime, as if there 
were no other phosphate present : and when, 
in fact, much of the phosphoric acid is com- 
bined actually and less profitably with alu- 
mina and oxide of iron. Such a presentment 
implies a character which is unreal, and 
practises a deception which is mean. Science, 
in its dignity, is regardless of all interests 
but those of truth and humanity. Its mission 
is to serve the good of mankind, and not the 
profit of an individual or class. The chemist, 
then, in his professional quality, is a high 
priest of science, who assumes, as a trust, 
the obligation of administering its rites with- 
out fear or favour in respect of results or 
persons ; and, in betraying this confidence, 
he becomes not only a false prophet, but 
deposes himself by the act from his sacred 
office. 



K K 



498 



PURE FERTILIZERS. 



Mor jit's Table of the Value of Crude PhospJiatcs of Lime of 
Different Grades. 



Per cent, of 
actual tri- 
phosphate 
of lime. 


Per cent, of 
profligate 
associates. 


Value of the raw 

mineral per 
unit of tri-phos- 
phate of lime. 


Per cent, of 
actual tri- 
phosphate 
of lime. 


Per cent, of 
profligate 
associates. 


Value of the raw 

mineral per 
unit of tri-phos- 
phate of lime. 






S. D. F. 






S. D. F. 


45 


55 


10 I 


77> 


27 


I 5 I 


46 


54 


10 2 


74 


26 


I 5 2 


47 


53 


10 3 


75 


25 


I 5 3 


48 


52 


II 


76 


24 


I 6 


49 


51 


II I 


77 


23 


I 6 I 


50 


50 


II 2 


78 


22 


I 6 2 


51 


49 


II 3 


79 


21 


I 6 3 


52 


48 


I 


80 


20 


I 7 


53 


47 


I I 


81 


19 


I 7 I 


54 


46 


I 2 


82 


18 


I 7 2 


55 


45 


I 3 


^l 


17 


I 7 3 


56 


44 


I I 


84 


16 


I 8 


57 


43 


I I I 


85 


15 


I 8 I 


58 


42 


I 1 2 


86 


14 


I 8 2 


59 


41 


I I 3 


^7 


n 


I 8 3 


60 


40 


I 2 


^^ 


12 


I 9 


61 


39 


I 2 I 


89 


II 


I 9 I 


62 


38 


I 2 2 


90 


10 


I 9 2 


63 


37 


I 2 3 


91 


9 


I 9 3 


64 


36 


I 3 


92 


8 


I 10 


65 


35 


I 3 I 


93 


7 


I 10 I 


66 


34 


I 3 2 


94 


6 


I 10 2 


67 


33 


I 3 3 


95 


5 


I 10 3 


68 


32 


I 4 


96 


4 


I II 


69 


31 


I 4 I 


97 


3 


I II I 


70 


30 


142 


98 


2 


I II 2 


71 


29 


I 4 3 


99 


I 


I II 3 


72 


28 


I 5 


100 





200 



COMMERCIAL VALUATION. 499 

Precipitated Phosphate of Lime. 

This being a pure, or nearly pure, product 
eliminated from the raw mineral phosphates 
at great expense, is much more valuable than 
any corresponding grade of natural phos- 
phate of lime. Being very sensitive to the 
atmospheric and solvent influences of the 
soil, it represents the potential condition of 
its class. In making the preceding table, 
only the bare expense of materials and 
manufacture, without margin for profit, was 
added to the first cost of the raw minerals, in 
order to fix the value of different grades of 
natural phosphate. For the reasons above 
noted, however, and also because there is a 
great economy secured, as to package and 
transportation charges, in connection with 
the pure concentrated artificial product, its 
value would be fairly computed by adding 
fifty per cent, to the figures noted in the 
table for natural phosphates. In other words, 
pure precipitated phosphate of lime has an 
actual worth of three shillings, at least, per 
unit. As it is inexpedient to dry out all its 
moisture, the presence of water, even to the 

K K 2 



500 PURE FERTILIZERS. 



extent of ten per cent., should not be con- 
sidered an impurity to degrade its quality 
and rating ; which latter, however, refers 
here to the anhydrous state. 

Colombian Phosphate of Lime. 

This form of precipitated phosphate of 
lime contains more or less di-phosphate, and, 
consequently, has a higher degree of potenti- 
ality. Its value is, therefore, greater, and 
will be fairly computed by calculating its 
total of phosphoric acid to lime, and esti- 
mating the equivalent of tri-phosphate of 
lime, thus deduced, according to the rule 
prescribed above for precipitated phosphate, 
— that is, at three shillings per unit. 

Di-phosphate of Lime. 

This phase of phosphate is met with only 
occasionally in Nature. In such instances, 
its phosphoric acid must be calculated to lime 
as tri-phosphate, and the equivalent thus 
deduced is then to be rated according to the 
table at p. 498. 

The artificial product requires a different 
consideration. By reason of its chemical 



MORFIT on .'hr ynnn/arliiir of'FertiliXffx 



Pan for Melting Stearic Pitch. 



■II. t^, >. 



:^ 



•^ 



T 






ic*i( a' ••!' 



COMMERCIAL VALUATION. 501 

tenderness, it is in the same category for 
potentiality as the Colombian Phosphate, 
but in higher degree. Though the cost of 
its preparation is not greater than that of the 
Colombian Phosphate, it contains a much 
larger ratio of phosphoric acid, and, there- 
fore, must be estimated accordingly. The 
proper way to determine its value will be to 
calculate its content of phosphoric acid to 
lime as tri-phosphate, and value its equiva- 
lent of the latter at three shillings per unit. 

As it contains about six and a half per 
cent, of constitutional water, and may hold, 
advantageously, as much more of accidental 
moisture to insure impalpability of powder, 
10 to 15 per cent, of water should not be 
allowed to disturb the valuation above 
given. Indeed, a product which does not 
contain more than 10 per cent, of water and 
10 per cent, of foreign matter is pure for all 
practical purposes. 

Bi-phosphate of Lime. 

The processes for making pure precipi- 
tated or di-phosphate of lime are so simple, 
economical, and advantageous, in all re- 



502 PURE FERTILIZERS. 

spects, that I do not recognize any other 
materials as a proper basis for the manufac- 
ture of bi- or superphosphate of lime. My 
views on this point have been set forth 
already in Chapters xiii and xiv. It is only 
necessary to remark now, that either precipi- 
tated, Colombian, or di-phosphate will yield 
a "superphosphate" of the highest possible 
quality at even a lower cost than the cheapest 
of crude mineral phosphates when great purity, 
concentrated form, and economy of packing 
and transportation are considered. The 
''superphosphate" of promiscuous composi- 
tion, therefore, as made from mineral phos- 
phates (often carrying 90 per cent, of w^orth- 
less matter, and even at the best, when pre- 
pared from good bone-ash, never richer than 
30'0 per cent, of anhydrous bi-phosphate of 
lime), is being pushed into merited disrepute 
by the chemical improvements of the day in 
connection with this subject. 

As made from the pure sources, " super- 
phosphate" will contain nothing but the 
chemical equivalent proportions of bi-phos- 
phate and sulphate of lime which rightly be- 
long to it. Its value, therefore, will be the 



COMMERCIAL VALUATION. 503 

first cost of the precipitate, plus that of the 
quantity of sulphuric acid required to convert 
it into bi-phosphate, with 10 per cent, added 
for profit. Thus, — 

100 tons of pure precipitated phosphate of lime - ;^i5oo 

^2 „ brown oil of vitriol of specific grav. r/oo 287 

Manufacturing expenses^ profit, etc. - - 150 



^1937 



The product is, quantitatively, 190 tons of 
" superphosphate", containing, practically, 39 
to 40 per cent, of actual bi-phosphate of lime, 
or CaO, 2HO, PO^ As commercial "super- 
phosphate", therefore, it is worth, say £10 
per ton, or five shillings per unit of actual 
bi-phosphate of lime. 

I have estimated the bi-phosphate of lime, 
with its constitutional water, as part of its 
formula, and for the reason that this water is 
an element of its nature, which cannot be 
alienated without modifying the properties of 
the original bi-phosphate disadvantageously. 

Pure Bi-phosphate of Lime. 

This salt is made from the preceding 
"superphosphate" by merely leaching it in 
water and evaporating to crystallization the 



504 PURE FERTILIZERS. 

solution of bi-phosphate thus obtained. loo 
tons of precipitated phosphate of lime give 
75 tons of pure bi-phosphate, at a cost of 
;^I987, plus lo per cent, for manufacturing 
expense. This makes a total of ;2^2200, 
which, divided by 75, gives ^^30 as the 
value per ton, or six shillings per unit of 
pure bi-phosphate of lime =CaO, 2HO, PO5. 

The usual commercial custom is to estimate 
the anhydrous bi-phosphate as equivalent to 
tri-phosphate of lime ; and, by this means, 
o'64i is made to appear as roo per cent. 
Such a valuation is fictitious, and could not 
be evolved under a just system of computa- 
tion. My figures will refer, therefore, to the 
actual bi-phosphate of lime as it exists, 
naturally, in the "superphosphate" or pure 
bi-phosphate of lime, according to the for- 
mula CaO, 2HO, PO5. 

Di-phosphate requires less acid than the 
precipitated phosphate of lime for its conver- 
sion into "superphosphate", but the product 
from it is much smaller, and this incident 
makes the two correspond closely in value as 
raw material for conversion into superphos- 
phate. But, as the "superphosphate" from 



COMMERCIAL VALUATION. 505 

di-phosphate of lime would contain a greater 
per centage of bi-phosphate than that made 
with precipitated tri-phosphate, a given 
weight of a product from the former will be 
worth more than a corresponding quantity 
of product from the latter. Degree and de- 
gree, the bi-phosphate from either source has 
the same value, which is five shillings per 
unit. 

But for the obstinate popular prejudice in 
favour of " super-" or " bi-phosphate", di- 
phosphate would come into general use as a 
substitute for them. It is much more econo- 
mical and fully as potential, if not quite as 
active, in fertilizing effect. Indeed, it is 
more than probable that most of the bi-phos- 
phate, which may be sown, ''goes back'' into 
di-phosphate long before the growing crop 
has had time to take it up and assimilate it. 

Phosphate of Magnesia. 

This is to be estimated according to its 
ratio of phosphoric acid and after the rules 
prescribed for the phosphates of lime, ac- 
cording as it may be in a mineral or arti- 
ficial state. 



5o6 PURE FERTILIZERS. 

Phosphate of Alumina. 

This salt, in its natural rocky state has 
only a commercial value; and, as "Alta Vela 
Guano" is the sole representative of its class, 
which comes to market at present in abun- 
dant and regular supply, it must be taken as 
the standard at the current price of £'^ : lo 
per ton of 35° phosphate strength, or one 
shilling per unit of phosphoric acid which it 
may contain. As the proportion of phospho- 
ric acid may fall, that of the alumina and 
foreign associates must rise ; and, conse- 
quently, the less valuable becomes the mine- 
ral. Owing to the uncertain composition of 
the phosphate of alumina as existing in this 
kind of mineral, the system of computing the 
value of the latter will be somewhat arbi- 
trary. It may be wholly meta-phosphate of 
alumina (AU O3, 3PO5), or a mixture of that 
and pyro-phosphate (2AI2 O3, 3PO5, loHO), 
when dried at 110°, together with more or 
less of free alumina. In any case, the greater 
the presence of alumina, the larger will be 
the quantity of acid required for the chemical 
treatment which it must undergo to become 



COMMERCIAL VALUATION. 507 

serviceable in agriculture or the arts. There- 
fore, the value of this class of minerals is to 
be gauged according to the content of alu- 
mina and the composition and cost of the 
" Alta Vela Guano" at the present market 
price or rate. But it is not difficult to make 
a scale upon this basis, for the presence of a 
very large quantity of constitutional water in 
most cases excludes any appreciable amount 
of foreign or profligate matters. The small 
margin thus left for the latter constituents is 
almost wholly filled by silica and oxide of 
iron. There is, therefore, no disturbing ele- 
ment of calculation, but the variableness of 
the ratio of alumina to the phosphoric acid. 

Assuming, then, as a starting-point, that 
the value of a mineral phosphate of alumina 
is one shilling per unit, when the ratios of 
alumina and phosphoric acid are as 33 to 31, 
and that there are no profligate constituents, 
for example, as in the '*Alta Vela Guano"; 
then, for eveiy gradation of the former down- 
wards, there will be a proportional rise in the 
value of the mineral. Thus, it is only neces- 
sary to calculate the actual cost of removing 
the alumina degree by degree, in order to 



5oS 



PURE FERTILIZERS. 



determine the improvement in value for pro- 
gressively augmenting ratios of phosphoric 



acid. 



Morfifs Tabic of tJic Commercial Value of Different Grades 
of Mineral Phosphate of Alnniina. 



Ratio of 
alumina. 


Ratio of 
phospho- 
ric acid. 


Value 
unit 


per 


Ratio of 
alumina. 


Ratio of 
phospho- 
ric acid. 


Value per 
unit. 






S. D. 


F. 






S. D. F. 


22-0 


310 


I 





17-0 


31-0 


I 8 3 


21'0 


31-0 


I I 


3 


i6-o 


31-0 


I 10 2 


20-0 


31-0 


I 3 


2 


15-0 


31-0 


2 I 


I9'0 


31-0 


I 5 


I 


14-0 


31-0 


230 


i8-o 


31-0 


I 7 





— 


— 


— 



A range has been given to these computa- 
tions which will comprise all the kinds of 
this mineral now known even by specimens 
only. As, however, the figures affixed refer 
exclusively to the phosphate of alumina in 
its crude state, there remains yet to explain 
the values of the phases of artificial phos- 
phate of alumina as made in the phosphate- 
sewage process (Chapters xx and xxi), or 
other method of precipitation from an acid 
solution of the raw mineral. Here the same 
principles come into play as for the precipi- 



COMMERCIAL VALUATION. 509 

tated phosphate of lime. The original rocky 
character of the mineral has changed to a 
soft pulpy condition, most tenderly sensitive 
to acids, alkalies, and the growing influences 
of vegetation ; so that, in fact, a new physical 
nature has been assumed. As, however, the 
chejnical composition of the precipitate will 
not differ materially from that of the alumina 
phosphate constituent of the original mineral, 
the values of the different grades will be 
fairly expressed by adding twenty-five per 
cent, to the several degree-computations of 
the preceding table. 

Phosphate of Iron. 

The values of the different grades of this 
constituent, whether natural or prepared arti- 
ficially, can only be estimated arbitrarily, but 
may safely be taken at half the rates com- 
puted for phosphate of alumina. 

In either of the two preceding cases the 
valuation refers to the purposes of sewage- 
defecation, the alum manufacture, and agri- 
culture ; for it will be seen in Chapters xviii, 
XIX, XX, and xxi, that both the phosphate of 
alumina and phosphate of iron are capable of 



510 PURE FERTILIZERS. 

many and profitable applications. Indeed, 
this wide range of practical usefulness makes 
the commercial appreciation of the phos- 
phates of alumina and iron much greater 
than their agricultural value. 

The remaining items pertaining to this 
subject are chlorides of potassium, sodium, 
and ammonium ; sulphates of potassa, soda, 
and lime ; nitrate of potassa and nitrate of 
soda, each of which has a current value 
varying with the supply and demand, as may 
be learned by reference to any market price- 
list of the day. 



CHAPTER XXV. 



THE MODE OF USING HYDROMETERS AND 
THERMOMETERS. 

A HYDROMETER is a Convenient glass instru- 
ment for measuring the density or specific 
gravity of fluids. It is often referred to 
throughout this work; for instance, in speak- 
ing of an acid, the strength is stated as 
being of so many degrees Baume or Twaddle; 
that is, it has a specific gravity correspond- 
ing with the degree to which the hydrometer 
sinks in the liquid. 

For those liquids lighter or rarer than 
water, viz., alcohol, ethers, and the like, the 
scale is graduated differently than for the 
heavier or more dense, examples of which 
latter are the acids, saline solutions, and 
syrups. There are several kinds of hydro- 
meters ; but that called Baume s is the most 
used, and to this my remarks will refer. 



5^2 



PURE FERTILIZERS. 



The scale for the liquids rarer than water 
is graduated upwards from o, at the bottom 
of the stem, as shown by fig. 21. For 
liquids denser than water, the graduation is 
reversed, as in fig. 22. 



Fin;. 21. 



Ficf. 2; 



As it would be troublesome, and with 
many impracticable, to estimate the specific 
gravities of liquids in a scientific way, these 
little instruments are a great convenience ; 
for, by taking out a portion of the fluid to be 
tested, and placing it in a tall glass cylinder 
(fig. 23), its degree Baume may be asccr- 



HYDROMETERS & THERMOMETERS. 513 

tained by noting the point to which a hydro- 
meter sinks therein. From this datum its 
specific gravity is deduced by calculation, 
according to the proper formula on p. 514. 




Fig. 23. 



For instance, suppose the hydrometer 
sinks in alcohol to 35^ then its specific 



L L 



514 PURE FERTILIZERS. 

gravity is 0*852, and this again can be 
translated into its absolute spirit strength by 
comparison with any accurately calculated 
alcohol table. 

So, also, if a hydrometer for liquid denser 
than water sinks in acid to 66°, it denotes 
that the acid has a specific gravity of i '846. 

The presence of foreign matters will cause 
the hydrometer to give a false indication, 
but for nearly pure liquids the instrument 
answers satisfactorily ; and, indeed, under 
all circumstances, it serves very well for 
noting a progressive increase or diminution 
in the strength of solutions or other liquids. 
The temperature of the liquid should be 
60° to 62" Fahrenheit, at the moment of 
testing it. 

The following rules, by Pile, in connection 
with hydrometers, will be found convenient : 

To convert Baume's degrees into specific gravity munbers. 
For liquids lighter than water. 

B°+'^34 ^ specific gravity. 

To convert specific gravity numbers into Baumes degrees* 
For liquids lighter than water. 

.. ^^ 1 34 = Bo. 

bp. grav. 



HYDROMETERS & THERMOMETERS. 515 

To convert Baume's degrees into specific gravity numbers. 
For liquids heavier than water. 
144 



144 



^= specific gravity. 



To convert specific gravity numbers into Baume's degrees. 
For Hquids heavier than water. 

144 - — ^^^^ = BO. 
sp. grav. 

For converting the degrees of Tzv addle s hydrometer into 
specific gravity numbers multiply by ^, and add i"OOo; 
thus — 

Twaddle "So" x 5 =400 + 1000= sp. grav. 1-400. 

For converting specific gravity numbers into the degrees of 
Tzuaddle's hydrometer deduct I'OOO, and divide by 5 ; 
thus — 

Sp. grav. 1*400- 1000 = ^^ — = Twaddle 80°. 

Vulcanite is now substituted, sometimes, 
for glass, in the manufacture of hydrometer 
and thermometer scales. Such instruments 
are much more durable in every respect. 
They may be purchased at Blaise and Co.'s, 
No. 67, St. James's Street, London. 

Thermometers. 

The thermometer is an instrument made 
wholly of glass, when intended for chemical 

L L 2 



i\ 



516 PURE FERTILIZERS. 

o) purposes. Fig. 24 shows one with the 
scale graduated upon porcelain en- 
amelled upon the tube, so that the de- 
grees may be easily read and the in- 
strument readily kept clean. It is a 
measurer of the variation of tempera- 
ture in bodies. The principle upon 
which it is constructed is the change 
of volume which takes place in bodies 
when their temperature undergoes an 
alteration, or, in other words, upon 
their expansion. In the construction 
of thermometers, the fluid employed 
for measuring the change of tempera- 
ture is usually metallic mercury, be- 
cause it expands uniformly and has a 
very wide interval between its freezing 
and boiling-points. 

There are several different thermo- 
metrical scales, all constructed upon 
the same principle, but varying in their 
graduation ; the boiling and freezing- 
points of each, though corresponding 
in fact, being represented by different 
numbers. 

The Fahrenheit scale is most used 

Fig. 24. 



HYDROMETERS & THERMOMETERS. 517 

in this country ; that of Celsius, called the 
centigrade, in France and the continent 
generally, except Spain and Germany, where 
Reaumur's scale is preferred. 

In the Fahrenheit thermometer, the inter- 
val between the freezing and boiling-points 
of water is divided into 180 degrees. The 
freezing-point is placed at 32*^, and hence 
the boiling-point at 32+ 180= 212*=*. Reau- 
mur divides the distance between the two 
extreme points of water into 80^, and Celsius 
spaces his thermometer (the Centigrade) into 
100 equal intervals, the zero point, as in 
Reaumur's, being placed at freezing. The 
Fahrenheit scale is most convenient, be- 
cause of the lesser value of its divisions ; 
but, as it frequently happens that the manu- 
facturer has no choice in the kind, but is 
compelled to take such as can be con- 
veniently obtained, I give formulae for con- 
verting the degrees of one into those of the 
others. 

In the graduation of the scale it is only 
necessary to have two fixed determinate tem- 
peratures, and for these the boiling and 
freezing - points of water are universally 



5i8 PURE FERTILIZERS. 

chosen. The scales can be extended beyond 
either of these points by continuing the 
graduation. Those degrees below zero or 
o*^ have the minus (— ) prefixed, to distin- 
guish them from those above : thus 55° F. 
means fifty-five degrees above zero, Fah- 
renheit's scale ; and —9^ C, nine degrees be- 
low zero, centigrade scale. The thermome- 
ters for general use, very seldom, however, 
extend either way beyond the boiling and 
freezing-points of water, but they are gra- 
duated sometimes to 400° or 600°. One 
of soo'^ Fahrenheit is cheaper and con- 
venient for general manufacturing purposes. 

The following rules will be found con- 
venient for converting the degrees of the 
several scales into each other : — 

To convert Centigrade into Fahrenheit 
degrees. 

Multiply by 9, divide by 5, and add 
32. 

To convert Centigi^ade into Reaumur de- 
grees. 

Multiply by 4, and divide by 5. 



HYDROMETERS & THERMOMETERS. 519 

To convert Reaumur into Fahrenheit de- 
grees. 

Multiply by 9, divide by 4, and add 32. 

To convert Reaumur into Centigrade de- 
grees. 

Multiply by 5, and divide by 4. 

To convert Fahrenheit into Centigrade 
degrees. 

Deduct 32, multiply by 5, and divide 
by 9. 

To cotivert Fahrenheit into Reaumur de- 
grees. 

Deduct 32, multiply by 4, and divide 
by 9. 



CHAPTER XXVI. 

WATER AND ACID-PROOF CEMENTS AND 
PAINTS. 

In the construction of mason-work for che- 
mical purposes, it is necessary that the 
cement employed shall be not only strong 
and durable, but proof against the action of 
water ; and, if possible, also resistant of the 
action of acids. The following means are 
the best known for accomplishing those re- 
quirements. 

Hydraulic Cement. 

The Portland Cement, as made in London 
and its vicinity, fulfils all these requirements, 
except the last, in more eminent degree than 
any other; and it is best to employ that 
kind. 

Without intending to discuss princi- 



DURABLE CEMENTS AND PAINTS. 521 

pies* which regulate the hydraulicity of 
cements, I will remark that the lime which 
is to be used for works which are to resist 
the action of water, must be made of a lime- 
stone containing a certain amount of clay 
and magnesia with some little manganese 
and iron. The proportion of these ingre- 
dients combined should bear the relation of 
20 to 30 per cent, of the carbonate of lime 
constituent. In a lime-stone of such a com- 
position the soluble silica, alumina, and 
magnesia, will be most likely to hold that 
proportional relation to the lime which seems 
necessary to a prompt and complete hydrau- 
licity of a cement. 

If there should be an excess of lime over 
and above the chemical proportion required 
to form the triple silicate of lime, alumina 
and magnesia which constitutes a good hy- 
draulic or water-cement, it would in time be 
washed out gradually by the water ; but the 

* According to Fremy, aluminate of lime plays a most 
important part in the hydraulicity of cements ; and he has 
reported the results of his researches on the subject, in the 
Journal de Pharmacie et de Chiuiie, at p. 20 of vol. 2 for 
1865. 



522 PURE FERTILIZERS. 

cement will remain hard, and unimpaired in 
strength and durability. 

In the event of there being no excess of 
lime, the silicate formed by mixing the 
cement with water will be so closely bound 
as to its constituents, that it will resist to a 
considerable degree even the decomposing 
action of acids. 

A very good hydraulic cement may be 
made according to the following formula. 

The ingredients are — best quality fat lime, 
68 to 74^ parts by weight ; refractory clay, 
271 to 42} ; sulphate of lime, 4f to 9*0 ; and 
boracic acid, 0*105 ^o 0*40 1. 

All the substances are calculated in the 
anhydrous state. The cements formed be- 
tween these limits vary in the rapidity with 
which they set, but are of equal quality, and 
attain, in the course of time, the same degree 
of hardness. The substances are mixed after 
being ground to a fine powder. They are 
then made into bricks with water, and are 
baked at a white heat. After this, they are 
reduced to an impalpable powder. This 
powder, mixed with water, is then used as 
the cement, cither plain or coloured, and can 
be moulded as required. 



DURABLE CEMENTS AND PAINTS. 523 



Bottger's Cement. 

This is a very good cement for sealing 
joints. It is made by mixing finely-powdered 
chalk with an aqueous solution of silicate of 
soda, of 33° Baume, so as to form a stiff 
mortar. It sets hard in six to ten hours. 

Sorer s Cement. 

This is a very hard cement, and will serve 
for sealing the joints of mason-work. It is 
a hydrated basic oxychloride of magnesium, 
prepared by mixing calcined magnesia with 
an aqueous solution of chloride of magne- 
sium of 20^^ to 30" Baume. The denser the 
solution, the harder will be the cement. 

Bituminous Cement, or Stearic Pitch. 

When the digester vats are built, they 
may be lined with the preceding cements if 
intended for solutions of a neutral character. 
But for operations of an acid nature they 
must be covered with a cement or paint of 
thorough protective power against the chemi- 
cal friction of acids. This coating must also 



524 PURE FERTILIZERS. 

have a high softening-point, more particu- 
larly where heat is to be used in the vessels 
painted with it. 

The material fulfilling more nearly than 
any other all these requirements, is the black 
pitchy residue obtained in the distillation of 
fats for the manufacture of stearic candles, 
and in the refining of "cotton oil foots". 
It is black, insoluble in water and acids, and 
retains its hardness so obstinately, that it is 
difficult to melt it alone at a temperature be- 
low 300° Fahrenheit. Being a refuse article, 
its market price is very low. 

In order to fuse it, a particular apparatus 
is necessary, as shown by Plate 28. It con- 
sists of a strong jacketed pan a a, made of 
wrought iron plate, and set in brick-work. 
This pan is heated by steam, which enters 
the jacket through the pipe b. The con- 
densed steam runs out through the tube c, 
which, during the heating, must be kept 
partly open by means of a cock as a safety- 
valve. 

The stirrer d is a wrought iron shaft rest- 
ing in a footstep at the bottom of the pan. 
Its blades or arms are of two kinds : the 



DURABLE CEMENTS AND PAINTS, 525 

lower ones being a series of loose scrapers of 
forged iron e e e, and c strung upon a rod f. 
This arrangement insures the scraping of the 
bottom of the pan and prevents accumulation 
of lumps of bitumen upon the heated surface 
of that portion of the metal ; while, at the 
same time, it is a protection against break- 
age, which might happen often, if the blade 
were more stiff, from the obstinate tenacity 
with which the pitch adheres to the metal 
when it is only partly melted. 

The upper blades gg, are made of a form 
to produce agitation of the contents of the 
pan, and also to scrape the sides, so as to 
keep them clean of adhering pitch. 

The stirrer is driven by steam, through 
means of the gearing h, affixed to a beam 
above. 

The pan, as shown by the plate, has the 
capacity for melting five hundredweight of 
pitch at each operation ; and four meltings 
may be made in twelve hours. 

The temperature required to effect the 
fusion being about 310° Fahrenheit, and, as 
the generator would have to be heated up to 
a pressure of sixty-five pounds per square 



526 PURE FERTILIZERS. 

inch, in order to give steam of that degree, 
it will be safer and more convenient to use 
a super-heater, as an auxiliary means. This 
apparatus, of inexpensive form, shown by o, 
at the side of the pan, consists of a coil 
made of very thick welded iron tubes k k, 
and put together by joints. 

The connections with the generator are 
shown at in, and with the pan at n. The 
whole is set in brick- work, with a furnace 
beneath, and this latter has a damper- 
arrangement for the management of the heat, 
according as steam of a moderately or very 
high temperature may be required. 

A little boiled linseed-oil will facilitate the 
fusion, but the addition of this fluid must 
be limited to ten per cent, of the pitch, for 
fear of lessening the hardness of the product. 
When the whole is fused and has become 
quite cold, it is to be thinned with spirits of 
turpentine or petroleum naphtha to such con- 
sistence as may be required. 

When the pitch is to be used as a cement 
it must be applied in its hot fluid state, and 
as thick as possible ; for which purpose, con- 
sequently, it should not contain any spirits 



DURABLE CEMENTS AND PAINTS. 527 

of turpentine. It takes several days to dry 
when mixed with oil alone ; but this objec- 
tion is countervailed by advantages. In this 
form it covers iron well with a coating which 
is very adhesive, though not even. 

To make an even coating, turpentine must 
be added, so as to thin the cement to the 
consistency of a paint, which may be applied 
readily with a brush. 

As the drying is very rapid, several suc- 
cessive coats may be put on in a day. 

This latter paint, applied thick and in 
several coats, is the protecting covering for 
iron and other vessels, which has been pre- 
scribed throughout this work. It may be 
made even without the aid of linseed-oil or 
the super-heater, by means solely of turpen- 
tine and at the ordinary temperature of the 
atmosphere. 

Vessels coated with this material will re- 
sist the action of acid liquors at temperatures 
even beyond 225° Fahrenheit. 

Marine Glue. 

This cement, which is proof against the 
action of both water and acids, may be made 



528 PURE FERTILIZERS. 

by heating gently one pound of india-rubber 
with twelve pounds of coal-tar, mixing 
thoroughly, and then adding and melting 
in twenty to twenty-four pounds of powdered 
shellac. The whole is then to be dipped 
out, and poured on a slab to cool. When 
used, it requires to be heated above 250° 
Fahrenheit. 

This cement is much more expensive and 
less advantageous than that made with the 
pitch from fats. Too frequent remelting 
spoils it. 

Substitute for Marine Glue. 

A good water and acid-proof cement may 
be made by melting together equal parts of 
gutta-percha and pitch, and casting into 
sheets or sticks on a plate. It may be made 
hard or soft by using less or more of gutta- 
percha. 

Cement to Resist Stdphuric Acid. 

Take caoutchouc, melt it by a gentle heat, 
treat with 6 to 8 per cent, by weight of 
tallow, taking care to keep the mass well 
stirred ; add dry slaked lime, so as to give 



DURABLE CEMENTS AND PAINTS. 529 

the fluid mass the consistency of soft paste ; 
and, lastly, stir in 20 per cent, of red lead, 
whereby the mass which would otherwise 
remain soft becomes hard and dry. This 
cement resists, according to Dr. Wagner, 
boiling sulphuric acid. 

A solution of caoutchouc, in twice its 
weight of raw linseed-oil, aided by heating, 
and the addition thereto of an equal weight 
of pipe-clay, yields a plastic mass, which also 
resists most acids. 

Cei lie Jits for Steam-Pipes. 
A very excellent cement, which is imper- 
meable by air or steam, and very suitable, 
therefore, for making tight the joints of 
steam-pipes, is made by kneading together 
into a perfect mixture the following ingre- 
dients : — 

Graphite, finely powdered - - 3 lbs. 

Lime, slackened and sifted - ~ 3 ., 

Sulphate of lime, in fine powder - 8 „ 

Boiled linseed oil - - - 7 »> 

Artificial Stone. 

A very excellent stone or cement may be 
made by melting together 200 pounds of 

jM m 



530 PURE FERTILIZERS. 

stearic pitch, 20 pounds of sulphur, and 
barely enough of spirits of turpentine to 
give it a thin pasty fluidity. At this stage, 
50 pounds of finely-powdered lime, 200 
pounds of ground plaster, and 25 cubic feet 
of very fine sand are to be added by degrees, 
and well stirred into the mixture, after which 
the mass is to be melted and pressed into 
bricks. This stone hardens in five to eight 
days. 



INDEX. 



Acid reservoir, the, 1 1 3 

Alabaster, 83 

Alkaline salts, estimation of, in mineral phosphates, 457 

Alma, M. de, 416 

Alta Vela guano, 50, 161, 223, 237, 246, 360-363, 395, 399, 
400, 402, 403, 406, 407, 409 ; analysis of, 364 ; treat- 
ment of for manure, 365 ; replaced by Morfit's "mother- 
liquor", 398 ; valuation of, 506, 507, 508 

Alum, from phosphate of alumina, 408 

Alumina, estimation of in mineral phosphates, 455 

phosphate of, not without fertilizing effect, 3 ; 

estimation of in mineral phosphates, 89, 408^ 414, 455 ; 
commercial valuation of, 506, 508 

phosphate, left in mother-liquor when phosphate 



of lime is precipitated,, 378 ; useful for defecation of 
sewage, 161, 402, 414; in manufacture of sugar, 415 ; 
in dyeing, 417 ; as glaze for pottery, 418 
phosphate of, Peter Spence's patent for treatment 



of mineral, 379 ; also J. Berger Spence and Peter 
Dunn's, 383, 385 ; also Townsend's^ 389 
and iron, formula for the chemical analysis of 



mineral phosphates of, 465 
Aluminate of soda, a ready saponifier, 409 
Aluminium, oxide of, 88 

M M 2 



532 INDEX. 

Ammonia, sources of, 44 ; wool, 44 ; leather clippings, 45 ; 

dried blood and flesh, 46 ; excreta, 47 ; sewage, 49, 

399, 406 ; atmospheric air, 488 
Ammonia, its defects as a precipitant of phosphate of lime, 

163 
crude liquor of, production and constitution of, 

39 ; estimates of evolution from coal, 40 ; separation 

from gas-liquor, 41-44 ; as an economiser, 284 

■ generator, the, 176 

hydrochlorate of, 57 

phosphate of, 41 

sulphate of, constitution and manufacture, 55, 



57 ; use as an economiser, 280, 284 
commercial valuation of, 486, 487, 488, 489 



Ammoniacal wash, 197 

Ammonium, chloride of, 7, 57 ; produced from sulphate 

of ammonia, 280 
Animal charcoal, 7 
Analysis, '' commerciar, meretricious character of, 465,496, 

497 
Analyses of— 

Apatite, by Hunt, 30 ; by Voelcker, 30 

German phosphorite, by Fresenius, 13 

Russian phosphorite, by Grewingk, 14 

Wicken coprolites, by Morfit, 17 

Pas de Calais coprolites, by Morfit and Gerland, 17 

Phosphorite, 30 

Suffolk and Cambridge coprolites, 30 

Sombrero guano, by Voelcker, 19 

Ditto, by Evans and Jones, 19 

Ditto, by Morfit, 30 

St. Martin's phosphate, by Voelcker, 20 

South Carolina phosphate, by Morfit and Gerland, 22,30 

Ditto, by Voelcker, 23 



INDEX. 533 

Analyses of — 

French phosphorite, by Voelcker, 25 

Navasa guano or Cooperite, by Morfit and Gerland, 
27, 30 

Bone-ash, by Morfit, 30 

Bone-black, by Morfit, 30 

Guaymas guano, by Morfit, 30 

Marlstones, by Morfit, 30 

Orchila guano, by Morfit, 30 

Rossa guano, by Morfit, 30 

Table of comparative composition of crude natural 
phosphates, 30, 31 

Wool, by Scherer, 44 

Brighton chalk, by Schweitzer, 64 

Tri-, di-, and bi-phosphates of lime, 68 

" Superphosphate", commercial, 289, 292, 293, 325 ; 
pure, 300, 301, 323 

Gerland's sulphite of tri-phosphate of hme, 341, 342,359 

Redonda guano, by Johnson, 364 

Alta Vela guano, by Voelcker, 364 

A. B. R. guano, 364 

Sewage-precipitate by sulphuric solution of Alta Vela 
guano, 400 ; by Morfit's "■ mother-water", 400 
Apatite, 2, 7, 290; characteristics and sources of, 9, 10 ; 

solubility of, 28 ; analysis of Canadian, 30 
A. R. B., a rock phosphate, 361 ; analysis of, 364; treat- 
ment for manure, 365 
Artificial stone, 530 
Austrian phosphorite, 13 



Bahia, nitrate of soda, 66 

Baking-powder, Horsford's, 327 ; directions for use, 334 

Baltic, the, 8 



534 INDEX. 

Barreswill on gas-liquor, 42 

Baumes hydrometer, 512 

Bavaria, 10, 11 

Bi-phosphate of lime, 73, 75, 303-314. 502, 503, 504 

Bituminous cement, 524 

Black Sea, the, 8 

Blair, Harrison, 123 

Blake's crusher, 96, 97 ; table of sizes of, 100 

Blood, dried, a source of ammonia, 46 

'' Blow-up, the", 229, 234, 241, 242, 244 

Bohemia, 10 

Boiler, steam, the, 109 

Bone-ash, the typical phosphate of lime, 2, (yj ; its sources, 
8 ; value as a fertilizer, 9 ; its solubility, 28 ; analysis 
of by Morfit, 31 ; the best material for '^superphos- 
phate", 200 ; but too good for the purpose, 291 ; 
method of analysis, 434; commercial valuation of, 489 

Bone-black, made by calcining bones, 7 ; value as a ferti- 
lizer, 9 ; analysis of by Morfit, 31 ; ammonia incident 
to its production, 44 ; its solubility in soil, 69 ; com- 
mercial valuation of, 490 

Bottger's cement, 523 

Bone-dust, commercial valuation of, 490 

Bread, brown, 336 ; gout and confectioners' cakes, 337 

Brighton chalk, 64 

Bristles, ammonia in, 44 



Calcium, chloride of, constitution and properties of, 81,85; 
reaction with sulphate of potassa, 86 ; how utilized, 
155, 277, 286 

■■ fluoride of, 84; estimation of in mineral phos- 
phates, 458 

oxide of, 61 



INDEX. 535 

Calcium, phosphate, sulphite of, 'j^ 

Cambridgeshire coprolites, 15 

Canadian apatite, 9, 10; coprohtes, 15 

Carolina, South, phosphates, 20; analysis of by Morfit and 

Gerland, 22, and by Voelcker, 23 ; 170, 202, 204, 206, 

208, 325 
Carr, Thomas, his disintegrator, 133, 244, 376 
Celsius's or centigrade thermometer, 518 
Cement for steam-pipes, 529 

Cements, water and acid proof, 520, 523, 528, 529, 530 
Cereal crops, fertilizer for, 426 
Chalk, 64 

Charcoal, animal, 7 ; peat, for sewage, 396 
Chemical analysis of phosphatic materials and products, 

formulae for, 432 
Chemistry, " commerciar, style of analytical, 465, 496, 497 
Chilian nitre, 66 

Chloro-phosphate of lime, Way's, 263 
Church, A. H., 2, 12 
Clark's enamel, 232 
Clegg, on ammonia in gas-liquor, 40 
Cliff, 127 

Collas, M., uses phosphate of alumina for dyeing, 417 
Colombian guano or phosphate, 71, 72, 75, 78, 130, 160, 

162, 216, 278, 301, 307; manufacture of, 203; first 

process, 204 ; the mother-liquor or wash, 221 ; second 

process, 222 ; formation of, 241, 298 
Confectioners' cakes, 337 

Cooperite or Navasa guano, 25, 237 : analysis of, 31 
Coprolites, 2; their nature and sources, 15, 16; Wickeu 

and Pas de Calais, analysis by Morfit and Gerland, 

17 ; value of, 494 

Deligny, 227; his process for di-phosphate of lime, 259-263 



536 INDEX. 

Digester, the, or solution vat, 117 

Digestion, first fractional, 165 ; second ditto, 169 

Di-phosphate of lime, 70, ^2, 226, 227, 238, 501 

Disinfectant, sulphite of tri-phosphate of lime as a, 353 

Disintegrator, Carr's, 133, 244, 300, 316, 323 

Dominique, his report on phosphate of alumina in the puri- 
fication of sugar, 416 

Dreschfeld, Dr. J., experiments with Gerland's sulphite of 
tri-phosphate of lime, 354 

Drying-kiln, the, 129 

Danger, universal, 426 

Dunn, Peter, 41 ; patent for treatment of mineral phos- 
phate of alumina, 383, 385, 408 

Dyeing, use of phosphate of alumina in, 417 

Dyer, W, J. T., 2, 12 

Elevator, the, 1 1 1 

Engine, the steam, 109 

Estremadura phosphorite, 1 1 

Etchelss, W. G., on supply and market values of woollen 

waste, 45 
Evans and Jones, analysis of Sombrero guano, 19 
Evaporating-pan, the, 131 
Excreta, human, a source of ammonia, 47 

Fahrenheit's thermometer, 517-519 

Factory plant, arrangement of, 147 

Feathers, ammonia in, 44 

Feltz, E., on sugar fertilizers, 428 

Fertilizers, normal, 425 ; universal dunger, 426 ; for cereal 
crops, 426; for leguminous plants, 427 ; for gramine- 
ous plants, 427 ; for sugar, 428 ; for root crops, 430 

compound, formula for analysis of, 469 



INDEX. 537 

Fertilizing materials, commercial valuation of, 485 

Filter vats, 171 

Flesh, dried, a source of ammonia, 46 

Fluoride of calcium or fluor spar, constitution of, and pre- 
sence in rock guanos, 15, 84; estimation of in mineral 
phosphates, 458 

Forbes's defecation of sewage by phosphates of alumina 
and iron, 395 ; should be supplemented by filtration 
through peat charcoal, 396 

Formulae for chemical analyses, 432 ; of phosphates of 
alumina and iron, 465 ; commercial "superphosphate", 
469; compound fertilizers, 470 

French coprolites, 15 ; phosphates, 24 

Fremy on cements, 521 

Fresenius, 13 ; analysis of German phosphates, 30 

Furnace, the roasting, 109 



Gas-liquor, as a source of ammonia, 40 ; its extensive pro- 
duction, 43 

Generator, the ammonia^ 176 

Geological distribution of the mineral phosphates, 2 

Gerland, Dr. B. W., analyses of Pas de Calais coprolites, 
17 ; of South Carolina phosphates, 22 ; of Cooperite 
or Navasa guano, 27 ; his sulphite of tri-phosphate of 
lime, 338; method of manufacture, 346; its properties, 
353'; and analysis, 356 

German phosphates, 11; coprolites, 15 

Gibbsite or Alta Vela guano, 361 

Glue, marine, 527, 528 

Gill, Haughton, on sugar, 430 

'"Going-back" of commercial "superphosphate", 293, 308, 
310, 505 

Gossage's coke-towers, 36 



538 INDEX. 

Gout bread, 337 

Gramineous plants, fertilizer for, 457 

Grewingk's analysis of Russian phosphorite, 14 

Grinding apparatus, 92 ; roller mill, 93 ; sifter, 95 ; Blake's 

crusher^ 97 ; Howel-Hannay mill, 102 
Guaymas guano^ 17, 71 
Gypsum, 83 

Hayti, 25 

Henry, Michael, 260 

Herepath, analysis of Suffolk coprolites, 31 

Horn, ammonia in, 44 

Horsford's baking-powder, 327 

Hosch and Enderisch's universal dunger, 426 

Howel-Hannay mill, 97, 102, 323 

Hunt, T. S., on apatite, 10; analysis of Canadian apatite, 30 

Hydraulic cement, 520 

Hydrochloric acid, its constitution and production, 36 ; 
Ure's table of specific gravities, 38; preferred to sul- 
phuric acid for solution of phosphates, 156 

Hydrometers, mode of using, 511 

Inertia, fertilizing, of certain mineral phosphates, 3 
Iron, oxide of, in mineral phosphates, 87, 453 
phosphate of, not without value as manure, 3 ; espe- 
cially when freshly precipitated, Z'^ ; estimation of in 
mineral phosphates, Zj, 451 ; left in mother-liquor 
when phosphate of lime has been precipitated, 378 ; 
conjoined with phosphate of alumina for sewage pre- 
cipitation, 402 
phosphate of, commercial valuation of, 509 

Johnson, analysis of Rcdonda guano, 364 



INDEX. 539 



Kamrodt, on sources of ammonia, 44 
Kiln, the drying, 129 
Knapp, on gas-liquor^ 42 



La Plata, 8 

Leather clippings a source of ammonia, 45 

Leguminous plants^ fertilizer for, 427 

Lerverd, A., et Cie., 127 

Liebig-Horsford baking-powder, 327 

Lift, the^ 1 12 

Limburg and Staffel phosphorite, 12 

Lime, constitution and diffusion of, 61 

carbonate of, its constitution and diffusion, G^,, 288 ; 

disadvantages of in association with phosphate of 
lime, 79-82 ; estimation of in mineral phosphates, 461 

chloro-phosphate of, 226 ; Way's process for produc- 
tion of, 263-276 

Colombian phosphate of, yZ, 203, 221, 241, 298, 500 

Gerland's sulphite of tri-phosphate of, 338 ; method 

of manufacture, 346; its properties, 353 ; analysis, 

356 

mineral phosphates of, method of analyses, 434 ; 

valuation of, 491. Table of their value per cent., 498 

organate of, 82 

phosphate of, its three chemical phases, 6^ ; tri- or 

bone-phosphate, 62> ; its solubility in the soil, 69 ; 
various characteristics, 70 ; pure rare in Nature, 290 ; 
errors or tricks in estimation of, 326, 432, Commer- 
cial valuation of, 493-497 

bi-phosphate of, 73 ; favoured by agriculturists, but 

inferior to precipitated phosphate, 75 ; production of 
pure and wholly soluble, 303-314. Commercial valua- 
tion of, 502, 503, 504 



540 INDEX. 

Lime, di- or neutral-phosphate of, 70-72 ; manufacture of, 
226 ; ought to have first place among fertilizers, 227 ; 
Morfit's process (A), 227 ; and process (B), 238. 
Commercial valuation of, 501 

precipitated phosphate of, its solubility in the soil, 

75 : its production and characteristics, 76-78 : pulpy 
condition, 157 ; only less potent than Colombian 
guano, 162 ; eminently suited for conversion into 
"superphosphate", 163 ; but almost too good for the 
purpose, 302. Valuation of, 499 

precipitated phosphate of, process of manufacture, 

164 ; the purge or first fractional digestion, 165 ; the 
solution or second fractional digestion, 169; the pre- 
cipitation and the vacuum filter vats, 171 ; the am- 
monia generator, 176; the ammoniacal wash or 
mother-liquor, 197 ; the purge-liquor, 199 

sulphite of, 340 

"superphosphate" of, principle of production of, 288; 

manufacture of commercial, 315-326; delusive analy- 
ses of, 325 

sulphate of, 65 ; constitution and presence in rock 

guanos, '^'^ 



Magnesia, phosphate of, 79; estimation of in mineral phos- 
phates, 454; commercial valuation of, 505 
Maracaibo, Colombian guano from, 71 
Marl-stones, 2, 7, 20, 30 
Marine glue, 527, 528 
Marschall, on sugar fertilizers, 429 
Martin's, St., phosphate, 20 
Mediterranean, the, 8 
Mill, the roller, 93 



INDEX. 541 

Mineral phosphates of lime, commercial valuation of, 491, 

492 
alumina, 3 ; standard for valuation 

of, 494-495 
commercial valuation of, 508 



Mixer^ the, 115 ; mixing machines, 132 

Monte-jus, the, 125, 169, 372 

Morfit's " mother-liquor" as substitute for Alta Vela and 

Redonda guanos, 398 ; comparative composition of 

several precipitates, 400 

table of the value of crude phosphates of lime, 498 

table of the value of crude phosphates of alumina, 

508 

Morris and Penny's ammonia process, 50-55 

Mother-liquor or wash and mode of reclaiming its mate- 
rials, 197, 221, 277-287; its merits in sewage defeca- 
tion, 223, 235, 243, 378, 398, 402-418 



Nassau phosphorite, 13 

Navasa guano or Cooperite, 25 ; analysis of by Morfit and 

Gerland, 27 ; by Morfit, 31, 237 
New Jersey, 10 
New York, 10 
Nitrate of soda, 66 
Norway, 9, 10 



Ogston, analysis of Spanish phosphate, 30 

Oil of vitriol, 32, 321 

Orchila guano, 27 ; analysis of by Morfit, 31 

Organate of lime, 82 

Organic matter in phosphates, 90 



542 



INDEX. 



Pan, the evaporating, 131 

Paints, water and acid proof, 526 

Passive condition of certain mineral phosphates, 3 

Pearl-ash^ 60 

Peat-charcoal, in the defecation of sewage, 396 

Penny and Morris's ammonia process, 50-55 

Peru, nitrate of soda from, 66 

Phosphate of ammonia, 41 

Phosphates, mineral, their wide diffusion in nature, i ; their 
constitution, 2 ; comparative solubility of, 28 ; must 
be finely powdered, 4 ; South Carolina, 20; analyses 
by Morfit and Gerland, 22, and Voelcker, 23 ; St. 
Martin's analysis by Voelcker, 20 ; French, 24 ; ana- 
lysed by Voelcker, 25 ; organic matter in, 90 ; sand 
and silica, 91, 442; v/ater, 91; South Carolina, 164, 
166, 170, 202, 204, 208, 494 ; Colombian, 203 

Phosphates, super, manufacture of, 288, 298-302, 315-326; 
delusive analyses of, 325 

of alumina. vSr^ Alumina 

of lime, analytical tables of, 30, 31. See Lime 

of magnesia. See Magnesia 



• of iron. See Iron 

of soda. See Soda 

Phosphorite, 2, 7 ; characteristics and sources of supply, 
11; Welsh, II ; German, 12; analysis, 13; Russian 
and Austrian, 13 ; Spanish, 290; analysis of Russian, 
14 ; and of Spanish, 30 

Phosphoric acid in sewage, 399 ; estimation of in mineral 
phosphates, 450 

Phosphorus, 226 

Pile, 514 

Pitch, stearic, 113, 231 

Plant, the, for manufacture of fertilizers, 108-146; arrange- 
ment of, 147-152; steam-boiler and engine, 109; 



INDEX. 543 

roasting-furnace, 109; platform and accessorieSj no; 
elevator^ in; lift, \\2 \ acid reservoir, w^; mixer, 
115 ; digester or solution vat, n/ ; syphon, 123 ; the 
monte-jus, 125 ; precipitation vat, 127 ; drying-kiln, 
129; wash-vat, 130; evaporating-pan, 131 ; mixing- 
machines, 132; Carr's disintegrators, 133-146; Poole 
and Hunt's mixer, 145 

Plaster of Paris, Z^^ 

Platform, the, and its accessories, 1 10 

Pockston on ammonia, 40 

Poole and Hunt, Baltimore, their mixer, 145 

Portland cement, 521 

Potassa, carbonate of, 60 

sulphate of, 58, 282, 283, 284 

Potassium, chloride of, 59 

Potential, the application of the term in this treatise, 486, 

499 
Pottery, phosphate of alumina as a glaze for, 418 

Precipitation, the, 171 

Process, Morfit's (A), 227 ; and (R), 238 

Profligate constituents of mineral phosphates, 493 

Purge, the, or first fractional digestion, 165 

liquor, the, 199 



Ransome's artificial stone, 155, 221, 278 

Redonda guano, 50, 237, 246, 287, 360, 361, 362, 371, 374, 
376, 379' 383. 385, 390, 395. 399' 400, 408 ; analysis 
of, 364, 466 ; treatment for manure, 365 ; P. Spence's 
treatment of, 379; also J. B. Spence and Dunn's, 383; 
Townsend's, 389 ; replaced by Morfit's " mother- 
liquor", 398; commercial valuation of, 508 

Reservoir, the acid, 1 13 



544 INDEX. 

Reynoso introduces phosphate of alumina to sugar- 
refining, 416 
Roasting-furnace, the, 109 
Rock guanos erroneously classified, 360 
Roller-mill, the, 93 
Reaumur's thermometer, 519 
Root crops, fertilizers for, 430 
Rossa or Guaymas guano, 17, 30, 71 
Russian phosphorite, 13 



Sal ammoniac, 57 

Salt, table, 409, 410 

Salt of tartar, 60 

Salts, alkaline, estimation of in mineral phosphates, 457 

Saponifier, a ready, in aluminate of soda, 409; method of 
use, 413 

Saxony, 10 

Scherer, on ammonia in wool, 44 

Schwachofter, on Russian phosphorite, 14 

Selinite, 83 

Sewage, the natural means of fertilization, i ; a source of 
ammonia, 47, 406 ; suggested method of treatment, 
47-49 ; phosphate of alumina for defecation of, 161 ; 
Morfit's "mother-water" an admirable precipitant of, 
223, 237, 402-418; its utilization a paramount problem 
of hygiene and economics, i, 393 ; analysis of pre- 
cipitates by Morfit, 400 

of the Thames, 393 

Shoddy a source of ammonia, 53 

Siebenthal, B. de, 164 

Sifter, the, 95 

Silver, nitrate of, 220 



INDEX. 545 

Soda, alumiiiate of, 409 

nitrate of, 66 

phosphate of, 48 ; as an economiser, 287 

Soda-lime, 51, 52 

Soil, elements of fertility in, 420 ; variety of fertilizers, 422 

Sombrero guano, 18; value first recognised by Morfit, 18 ; 
analyses by Voelcker, 18, Evans and Jones, 19, and 
Morfit, 31 

SoreFs cement, 523 

Spanish phosphorite, 290 

Spence, John Berger, 41 ; his patent for treatment of 
phosphate of alumina, 383, 385, 408 

Peter, his process for producing alum from phos- 
phate of alumina, 379, 408 

Stassfurt, 59 

Steam-boiler and engine, 109 

Stearic pitch, 113, 231, 523 

Suffolk coprolites, 15 

Sugar, phosphate of alumina, use in manufacture of, 415 ; 
fertilizers for, 428 

Sugar-cane, the, cited, 416 

Sulphite of calcium phosphate, ^^ 

Stone, artificial, 530 

Sulphite of tri-phosphate of lime, Gerland's, 338 ; method 
of manufacture, 346; its properties, 353; analysis, 
356 

Sulphuric acid, its slovenly use in treating mineral phos- 
phates, 4; constitution and manufacture of, 32; tables 
of specific gravity, 34, 35 

Superphosphate of lime, manufacture of, 288, 298, 315, 326; 
formula for analysis of, 469 

Sweden, 9 

Switzerland, 10 

Syphon, the, 123 

N N 



546 INDEX. 

Thames sewage, 393 

Thermometers, mode of using, 515 

Tounsend, Joseph, his conversion of Redonda guano into 

phosphate of soda, 287 ; his patent for treatment of 

phosphate of alumina, 389, 408 
Turbines, 310 
Twaddle's hydrometer, 515 



Universal dunger, 426 

Ure, sulphuric acid table, 35 ; hydrochloric acid table, 38 



Vacuum filters, the, 17 1 

Valuation of crude and refined fertilizing materials, 485 

Vat, cast-iron, 232 

Vat, the solution, 117; the precipitation, 127; the wash, 
130 

Vats, the filter, 171 

Venezuela, 27 

Vitriol, oil of, 32, 321 

Voelcker, Dr. Augustus, on apatite, 10 ; analysis of Ger- 
man phosphorite, 13 ; of Sombrero guano, 18 ; of St. 
Martin's phosphate, 20; of South Carolina phosphate, 
23 ; of French phosphate, 25 ; of Alta Vela guano, 
364 ; on soils and drainage, 43 1 



Wagner, 529 

Wanklyn, analysis of Way's di-phosphate of lime, 247 
Warrington on action of carbonate of lime, 80 ; on coagu- 
lation of alumina salts by hot water, 471 
Wash-vat, the, 130 



INDEX. 547 

Way, J. T., analysis of Cambridge coprolites, 3 1 ; his pro- 
cess for di-phosphate of lime, 227, 247-259 ; and for 
chloro-phosphate of lime, 263-276 

Welsh phosphorite, 1 1 

Whiting, 64 

Wicken coprolites, 16, 17, 494 

Williams, Charles P., on solubility of crude phosphates of 
lime, 28 

Williman's Island, 22 

Wool, as a source of ammonia, 44 

Woollen waste, 45 

Wright, on ammonia, 40 



THE END. 



T. KICHARDS, 37, GREAT QUEEN STREET, LONDON. 



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